Pharmaceutical compounds

ABSTRACT

The invention provides a compound for use in the treatment of T-Cell Acute Lymphoblastic Leukaemia (T-ALL), the compound having the formula (1): 
     
       
         
         
             
             
         
       
         
         or being a pharmaceutically acceptable salt thereof; wherein: 
         n is 0, 1 or 2; 
         Ar 1  is selected from an optionally substituted phenyl, pyridyl, thienyl and furanyl; 
         Q 1  is selected from C(═O), S(═O) and SO 2 ; 
         A is absent or is NR 2 ; 
         R 1  is selected from:
       hydrogen;   an optionally substituted C 1-6  non-aromatic hydrocarbon group; and   optionally substituted 3- to 7-membered non-aromatic carbocyclic and heterocyclic rings containing one or two heteroatom ring members selected from O, N and S, and bridged bicyclic heterocyclic rings of seven to nine ring members of which one or two are nitrogen atoms, the carbocyclic and heterocyclic rings and bridged bicyclic heterocyclic rings;   
     
         R 2  is selected from hydrogen and C 1-4  alkyl; or 
         NR 1 R 2  forms an optionally substituted 4- to 7-membered non-aromatic nitrogen-containing heterocyclic ring optionally containing a second heteroatom ring member selected from nitrogen and oxygen.

This invention relates to compounds for use in the treatment of T-cellacute lymphoblastic leukemias, and cancers (such as hematopoieticcancers) which depend on the Janus kinase TYK2 for cancer cell survival.

BACKGROUND OF THE INVENTION

T-Cell Acute Lymphoblastic Leukaemia (T-ALL) is a rare type of leukaemiathat usually occurs in late childhood or early adolescence and issignificantly more common in boys than girls. T-ALL is estimated toaccount for 10% to 15% of pediatric acute lymphoblastic leukaemia (ALL)cases and around 200 people are diagnosed with T-ALL in the UK everyyear. It is aggressive and progresses quickly: about 30% of T-ALLpatients relapse within the first year during or following treatment andeventually die.

As the name suggests, T-cell acute lymphoblastic leukemia affects a typeof white blood cell known as T-cells. Recurrent chromosomalabnormalities are a hallmark of acute lymphoblastic leukaemias andgenetic analyses of T-ALL have uncovered a substantial heterogeneity ingenetic abnormalities including chromosomal translocations, deletions,amplifications, and mutations (Armstrong et al., Journal of ClinicalOncology, Vol. 23, No. 26, pp 6306-6315 (2005).

These genetic abnormalities result in the aberrant expression oftranscription factors such as the basic helix-loop-helix (bHLH) genesMYC, TAL1(SCL), TAL2, LYL1, or bHLHB1; genes involved in transcriptionalregulation such as the cysteine-rich LIM-domain-only genes LMO1 or LMO2;or the Krüppel-like zinc-finger gene BCL11B. Abnormalities can alsoaffect genes that are involved in embryonic development such as thehomeodomain genes HOX11/TLX1 and HOX11L2/TLX3; members of the HOXAcluster; as well as signalling molecules such as the tyrosine kinaseABL13-6. Other translocations lead to the formation of specific fusionproducts and include CALM-AF109 or MLL rearrangements. Mutationalmechanisms may also enhance gene activity as, for example, activatingmutations in the NOTCH1 gene have been identified in about 50% of humanT-ALLs.

Current therapy for T-ALL consists of three stages: Remission induction,consolidation, and maintenance. Remission induction is intended to ridthe blood and bone marrow of leukaemia cells, requires intensivechemotherapy and involves a hospital stay of approximately 1 month.Different combinations of chemotherapy may be used, but typicallyinvolve vincristine, dexamethasone or prednisone, and doxorubicin ordaunorubicin (or a similar anthracycline). Depending on the patient'sprognostic factors, regimens may additionally involve cyclophosphamide,etoposide and/or high doses of methotrexate or cytarabine. Theseintensive treatments kill off many of the normal bone marrow cells aswell as the leukaemia cells, thus serious infections or othercomplications can occur during this phase. CNS treatment or prophylaxisis often started during the induction phase. Most often this involvesintrathecal chemotherapy (most commonly methotrexate), potentiallyalongside high-dose IV methotrexate or cytarabine, and radiation therapyto the brain and spinal cord.

Frequently, T-ALL goes into remission following the induction phase but,because a small number of leukaemia cells often survive the remissioninduction, a period of consolidation follows. Typically, this is a shortcourse of chemotherapy using many of the drugs used during induction,and typically lasts for a few months. The drugs are usually given inhigh doses so that this phase of treatment is still intensive. CNStreatment may be continued during this phase. Certain patients inremission may be given the option of an allogeneic stem cell transplant(SCT), especially those with a brother or sister who would be a gooddonor match. An autologous SCT may be offered to those without asuitable donor. SCT is a highly risky procedure that may not benefitevery patient.

After a period of consolidation, patients are generally put on amaintenance chemotherapy programme of methotrexate and 6-mercaptopurine.Occasionally this is combined with other drugs such as vincristine andprednisone. Maintenance usually lasts for about 2 years and CNStreatment may continue during this time.

Protein kinases constitute a large family of structurally relatedenzymes that are responsible for the control of a wide variety of signaltransduction processes within the cell (Hardie and Hanks (1995) TheProtein Kinase Facts Book. I and II, Academic Press, San Diego, Calif.).The kinases may be categorized into families by the substrates theyphosphorylate (e.g., protein-tyrosine, protein-serine/threonine, lipids,etc.). Sequence motifs have been identified that generally correspond toeach of these kinase families (e.g., Hanks and Hunter, FASEB J., (1995)9. 576-596; Knighton, et al., Science, (1991) 253, 407-414; Hiles, etal., Cell, (1992) 70, 419-429; Kunz, et al., Cell, (1993) 73, 585-596;Garcia-Bustos, et al., EMBO J., (1994) 13, 2352-2361).

Protein kinases may be characterized by their regulation mechanisms.These mechanisms include, for example, autophosphorylation,transphosphorylation by other kinases, protein-protein interactions,protein-lipid interactions, and protein-polynucleotide interactions. Anindividual protein kinase may be regulated by more than one mechanism.

Kinases regulate many different cell processes including, but notlimited to, proliferation, differentiation, apoptosis, motility,transcription, translation and other signalling processes, by addingphosphate groups to target proteins. These phosphorylation events act asmolecular on/off switches that can modulate or regulate the targetprotein biological function. Phosphorylation of target proteins occursin response to a variety of extracellular signals (hormones,neurotransmitters, growth and differentiation factors, etc.), cell cycleevents, environmental or nutritional stresses, etc. The appropriateprotein kinase functions in signalling pathways to activate orinactivate (either directly or indirectly), for example, a metabolicenzyme, regulatory protein, receptor, cytoskeletal protein, ion channelor pump, or transcription factor. Uncontrolled signalling due todefective control of protein phosphorylation has been implicated in anumber of diseases, including, for example, inflammation, cancer,allergy/asthma, disease and conditions of the immune system, disease andconditions of the central nervous system, and angiogenesis.

The Janus kinase (JAK) family is a family of intracellular non-receptortyrosine kinases, ranging in size from 120-140 kDa, that transducecytokine-mediated signals via the JAK-STAT pathway. The JAK family playsa role in the cytokine-dependent regulation of proliferation andfunction of cells involved in immune response. Currently, there are fourknown mammalian JAK family members: JAK1, JAK2, JAK3 and TYK2. JAK1,JAK2 and TYK2 are ubiquitously expressed whereas JAK3 is expressed inthe myeloid and lymphoid lineages. The JAK family members arenon-receptor tyrosine kinases that associate with many hematopoietincytokines, receptor tyrosine kinases and GPCR's.

Each JAK kinase protein has a kinase domain and a catalytically inactivepseudo-kinase domain. The JAK proteins bind to cytokine receptorsthrough their amino-terminal FERM (Band-4.1, ezrin, radixin, moesin)domains. After the binding of cytokines to their receptors, JAKs areactivated and phosphorylate the receptors, thereby creating dockingsites for signalling molecules, especially for members of the signaltransducer and activator of transcription (STAT) family (Yamaoka et al,2004. The Janus kinases (Jaks). Genome Biology 5(12): 253).

In mammals, JAK1, JAK2 and TYK2 are ubiquitously expressed. The role ofTYK2 in the biological response to cytokines has been characterizedusing a mutant human cell line that was resistant to the effects of TypeI interferons (IFNs) and by demonstrating that IFNα responsiveness couldbe restored by genetic complementation of TYK2 (Velazquez et al, 1992.Cell 70, 313-322). Further in vitro studies have implicated TYK2 in thesignalling pathways of multiple other cytokines involved in both innateand adaptive immunity. However, analysis of TYK2^(−/−) mice revealedless profound immunological defects than were anticipated (Karaghiosoffet al, 2000. Immunity 13, 549-560; Shimoda et al, 2000. Immunity 13,561-671). Surprisingly, TYK2 deficient mice display merely reducedresponsiveness to IFNα/β and signal normally to interleukin 6 (IL-6) andinterleukin 10 (IL-10), both of which activate TYK2 in vitro. Incontrast, TYK2 was shown to be essential for IL-12 signalling with theabsence of TYK2 resulting in defective STAT4 activation and the failureof T cells from these mice to differentiate into IFNy-producing Th1cells. Consistent with the involvement of TYK2 in mediating thebiological effects of Type I IFNs and IL-12, TYK2^(−/−) mice were moresusceptible to viral and bacterial infections.

Overexpression of TYK2 kinase has been implicated in the development ofsome disease states. For example, elevated levels of TYK2 were found inpatients suffering from progressive pulmonary sarcoidosis (Schischmanoffet al., Sarcoidosis Vasc. Diffuse, 2006, 23(2), 101-7).

It has been reported that JAK1 kinase is mutated in 18% of adultpatients suffering from T-ALL (E. Flex et al., Journal of ExperimentalMedicine, 2008, 205:751-758. It has also been separately reported thatT-cell acute lymphoblastic leukemias (T-ALL) account for about 15 to 25%of acute lymphoblastic leukemias in children and adults (Chiaretti etal, “T-Cell acute lymphoblastic leukemia”, (2009), 94(2), 160-162).Ciarretti et al. have suggested that JAK inhibitors and in particularJAK2 inhibitors may play a role in T-ALL treatment.

Sanda et al. have reported that there is a pathway dependence on TYK2and its downstream effector STAT1 in many (but not all) T-cell acutelymphoblastic leukemias (Sanda et al., “TYK2-STAT1-BCL2 PathwayDependence in T-cell Acute Lymphoblastic Leukemia”, (2013), CancerDiscov., 3(5), pp 564-577). Sanda et al. concluded that activation ofthe TYK2-STAT1 pathway in T-ALL cells occurs by gain-of-function TYK2mutations or activation of interleukin (IL)-10 receptor signalling andthat this pathway mediates T-ALL survival through upregulation of theanti-apoptotic protein BCL2. It had previously been reported(Coustan-Smith el al., “Clinical Relevance of BCL-2-Overexpression inChildhood Acute Lymphoblastic Leukemia”, (1996), Blood, 87(3), pp1140-1146) that BCL2 (B-cell lympoma 2) protein suppressed apoptosis andthat elevated levels of BCL2 have been identified in acute lymphoblasticleukemia. Sanda et al. (idem) proposed the development of moleculartherapies targeting TYK2 and tested three JAK inhibitor compounds(identified only as JAK Inhibitor I, AG490 and CP-690550) havingdiffering degrees of efficacy against TYK2 compared with other JAKfamily members. JAK Inhibitor I, which exhibits potent activity againstall JAK family kinases, including TYK2, was found to be effective atinhibiting growth of TYK2 dependent cell lines with IC₅₀ values rangingfrom 1-3 μM, whereas a TYK2-independent cell line (LOUCY) was found tobe insensitive. The compound AG490, another pan-JAK family inhibitor,produced similar results whereas the compound CP-690550, which is apotent inhibitor of JAK2 and JAK3 but not TYK2, was ineffective againstthe T-ALL cells.

Several JAK family inhibitors have been reported in the literature whichmay be useful in the medical field (Ghoreschi et al, 2009. Immunol Rev,228:273-287). It has been proposed that a selective TYK2 inhibitor thatinhibits TYK2 with greater potency than JAK2 may have advantageoustherapeutic properties, because inhibition of JAK2 can cause anemia(Ghoreschi et al, 2009. Nature Immunol. 4, 356-360).

WO2012/000970 (Cellzome) discloses a series of triazolopyridines as TYK2kinase inhibitors. WO2011/113802 (Roche) discloses a series ofimidazopyridines as TYK2 kinase inhibitors. The properties of JAKkinases and their relevance as therapeutic targets are also disclosed inWO2008/156726, WO2009/155156, WO2010/005841 and WO2010/011375, all inthe name of Merck.

WO2010/055304 and EP2634185 (both in the name of Sareum) disclose afamily of substituted oxazole carboxamides for use in the prophylaxis ortreatment of autoimmune diseases and in particular multiple sclerosis.The compounds disclosed in WO2010/055304 are described as being FLT3kinase inhibitors. The kinase inhibiting effect of oxazole carboxamidesis also disclosed in International patent application WO2008/139161(Sareum). WO2015/032423 (Sareum) discloses the use of a subset ofoxazole carboxamides compounds as TYK2 kinase inhibitors. The compoundsare described as being useful in the treatment of inflammatory andimmunological disorders such as autoimmune diseases.

T-ALL is an aggressive and rapidly progressing leukaemia associated withpoor patient prognoses and for which there are currently few reallyeffective treatments. At present, therefore, remains a need for newchemotherapeutic agents for the treatment of T-ALL and, in particular,chemotherapeutic agents that not only are effective against TYK2dependent T-ALL cells but also are effective inhibitors of at least someTYK2 independent cell lines.

The Invention

It has now been found that a group of oxazole carboxamides havingactivity against TYK2 kinases have biological activity that suggeststhey will be useful in the treatment of T-ALL. Moreover, it has beenfound that the compounds are active not only against TYK2-dependentT-ALL cell lines but also against some TYK2-independent T-ALL cells.

Accordingly, in a first embodiment (Embodiment 1.1), the inventionprovides a compound for use in the treatment of T-Cell AcuteLymphoblastic Leukaemia (T-ALL), the compound having the formula (1):

or being a pharmaceutically acceptable salt thereof; wherein:

n is 0, 1 or 2;

Ar¹ is selected from phenyl, pyridyl, thienyl and furanyl, each of whichis optionally substituted with one, two or three substituentsindependently selected from halogen, C₁₋₄ alkyl, hydroxyl-C₁₋₄ alkyl,C₁₋₂ alkoxy-C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₂ alkoxy-C₁₋₄ alkoxy, C₂₋₄alkenyl, C₂₋₄ alkenyloxy, C₂₋₄ alkynyl, C₂₋₄ alkynyloxy, cyano, C₁₋₄alkanoyl, hydroxy and C₁₋₄ alkanoyloxy, wherein the C₁₋₄ alkyl and C₁₋₄alkoxy moieties are each optionally substituted with one or morefluorine atoms;

Q¹ is selected from C(═O), S(═O) and SO₂;

A is absent or is NR²;

R¹ is selected from:

-   -   hydrogen;    -   a C₁₋₆ non-aromatic hydrocarbon group optionally substituted        with one or more substituents selected from hydroxyl, C₁₋₂        alkoxy, amino, mono-C₁₋₄ alkylamino, di-C₁₋₄ alkylamino, 3- to        7-membered non-aromatic carbocyclic and heterocyclic rings        containing one or two heteroatom ring members selected from O, N        and S, and bridged bicyclic heterocyclic rings of seven to nine        ring members of which one or two are nitrogen atoms, the        carbocyclic and heterocyclic rings and bridged bicyclic        heterocyclic rings being optionally substituted with one or more        hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄ alkanoyl, C₁₋₄        alkanoyloxy, C₁₋₄ alkoxycarbonyl or hydroxyl-C₁₋₃ alkyl groups;        and    -   3- to 7-membered non-aromatic carbocyclic and heterocyclic rings        containing one or two heteroatom ring members selected from O, N        and S, and bridged bicyclic heterocyclic rings of seven to nine        ring members of which one or two are nitrogen atoms, the        carbocyclic and heterocyclic rings and bridged bicyclic        heterocyclic rings being optionally substituted with one or more        hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄ alkanoyl, C₁₋₄        alkanoyloxy, C₁₋₄ alkoxycarbonyl, amino-C₁₋₃alkyl, mono-C₁₋₂        alkylamino-C₁₋₃ alkyl, di-C₁₋₂ alkylamino-C₁₋₃ alkyl or        hydroxyl-C₁₋₃ alkyl groups;

R² is selected from hydrogen and C₁₋₄ alkyl; or

NR¹R² forms a 4- to 7-membered non-aromatic nitrogen-containingheterocyclic ring optionally containing a second heteroatom ring memberselected from nitrogen and oxygen, the heterocyclic ring beingoptionally substituted with one or more hydroxy, C₁₋₄ alkyl, C₁₋₄alkanoyl, C₁₋₄ alkanoyloxy, C₁₋₄ alkoxy, C₁₋₄ alkoxycarbonylamino-C₁₋₃alkyl, mono-C₁₋₂ alkylamino-C₁₋₃ alkyl, di-C₁₋₂alkylamino-C₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl groups.

Particular compounds for use in treating T-ALL in accordance with theinvention are set out below in Embodiments 1.2 to 1.88.

1.2 A compound according to Embodiment 1.1 wherein n is selected from 0and 1.

1.3 A compound according to Embodiment 1.1 wherein n is 0.

1.4 A compound according to Embodiment 1.1 wherein n is 1.

1.5 A compound according to Embodiment 1.4 wherein the fluorine atom isattached to the benzene ring at a position ortho with respect to themoiety Q¹.

1.6 A compound for use according to any one of Embodiments 1.1 to 1.5wherein Ar¹ is optionally substituted phenyl.

1.7 A compound for use according to any one of Embodiments 1.1 to 1.5wherein Ar¹ is optionally substituted pyridyl.

1.8 A compound for use according to any one of Embodiments 1.1 to 1.5wherein Ar¹ is optionally substituted thienyl.

1.9 A compound for use according to any one of Embodiments 1.1 to 1.5wherein Ar¹ is optionally substituted furanyl.

1.10 A compound for use according to any one of Embodiments 1.1 to 1.9wherein the optional substituents for Ar¹ are independently selectedfrom halogen, C₁₋₄ alkyl, hydroxy-C₁₋₄ alkyl, C₁₋₂ alkoxy-C₁₋₄ alkyl,C₁₋₄ alkoxy, C₁₋₂ alkoxy-C₁₋₄ alkoxy, C₂₋₄ alkenyl, C₂₋₄ alkenyloxy,C₂₋₄ alkynyl, C₂₋₄ alkynyloxy, cyano, C₁₋₄ alkanoyl, hydroxy and 01-4alkanoyloxy, wherein the C₁₋₄ alkyl and C₁₋₄ alkoxy moieties are eachoptionally substituted with one or more fluorine atoms.

1.11 A compound for use according to Embodiment 1.10 wherein theoptional substituents for Ar¹ are independently selected from halogen,C₁₋₃ alkyl, hydroxy-C₁₋₃ alkyl, C₁₋₂ alkoxy-C₁₋₃ alkyl, C₁₋₃ alkoxy,C₁₋₂ alkoxy-C₁₋₃ alkoxy, cyano, C₁₋₃ alkanoyl and C₁₋₃ alkanoyloxy,wherein the C₁₋₃ alkyl and C₁₋₃ alkoxy moieties are each optionallysubstituted with one or more fluorine atoms.

1.12 A compound for use according to Embodiment 1.11 wherein theoptional substituents for Ar¹ are independently selected from fluorine,chlorine, bromine, C₁₋₃ alkyl, hydroxy-C₁₋₃ alkyl, methoxy-C₁₋₃ alkyl,C₁₋₃-alkoxy, methoxy-C₁₋₃ alkoxy, cyano, C₁₋₃ alkanoyl and C₁₋₃alkanoyloxy, wherein the C₁₋₃ alkyl and C₁₋₃ alkoxy moieties are eachoptionally substituted with one or more fluorine atoms.

1.13 A compound for use according to Embodiment 1.12 wherein theoptional substituents for Ar¹ are independently selected from fluorine,chlorine, bromine, methyl, ethyl, isopropyl, hydroxymethyl,hydroxyethyl, methoxyethyl, methoxy, ethoxy, isopropoxy, methoxyethoxy,cyano, acetyl, acetoxy, trifluoromethyl, trifluoromethoxy,difluoromethyl and difluoromethoxy.

1.14 A compound for use according to Embodiment 1.13 wherein theoptional substituents for Ar¹ are independently selected from fluorine,chlorine, methyl, ethyl, isopropyl, hydroxymethyl, methoxy, ethoxy,isopropoxy, cyano, acetyl, acetoxy, trifluoromethyl, trifluoromethoxy,difluoromethyl and difluoromethoxy.

1.15 A compound for use according to Embodiment 1.14 wherein theoptional substituents for Ar¹ are independently selected from fluorine,chlorine, methyl, ethyl, methoxy, cyano, acetyl and trifluoromethyl.

1.16 A compound for use according to Embodiment 1.15 wherein theoptional substituents for Ar¹ are independently selected from fluorineand chlorine.

1.17 A compound for use according to Embodiment 1.16 wherein eachsubstituent is fluorine.

1.18 A compound for use according to any one of Embodiments 1.1 to 1.17wherein Ar¹ is unsubstituted or has 1, 2 or 3 substituents.

1.19 A compound for use according to Embodiment 1.18 wherein Ar¹ isunsubstituted.

1.20 A compound for use according to Embodiment 1.18 wherein Ar¹ has 1substituent.

1.21 A compound for use according to Embodiment 1.18 wherein Ar¹ has 2substituents.

1.22 A compound for use according to Embodiment 1.18 wherein Ar¹ has 3substituents.

1.23 A compound for use according to Embodiment 1.18 wherein Ar¹ isunsubstituted or has 1 or 2 substituents.

1.24 A compound for use according to any one of Embodiments 1.1 to 1.6,1.10 to 1.21 and 1.23 wherein Ar¹ is an unsubstituted phenyl group or a2-monosubstituted, 3-monosubstituted, 4-monosubstituted, 2,3disubstituted, 2,4 disubstituted, 2,5 disubstituted or 2,6 disubstitutedphenyl group.

1.25 A compound for use according to Embodiment 1.24 wherein Ar¹ isselected from unsubstituted phenyl, 2-fluorophenyl, 2-hydroxyphenyl,2-methoxyphenyl, 2-methylphenyl, 3-fluorophenyl, 3-methoxyphenyl,2,6-difluorophenyl, 2-fluoro-3-methoxyphenyl, 2-fluoro-5-methoxyphenyl,2-chloro-6-methoxyphenyl, 2-fluoro-6-methoxyphenyl, 2,6-dichlorophenyl,2-chloro-6-fluorophenyl, and 5-fluoro-2-methoxyphenyl.

1.26 A compound for use according to Embodiment 1.25 wherein Ar¹ isselected from 2,6-difluorophenyl, 2-chloro-6-fluorophenyl and2,6-dichlorophenyl.

1.27 A compound for use according to Embodiment 1.26 wherein Ar¹ is2,6-difluorophenyl.

1.28 A compound for use according to Embodiment 1.26 wherein Ar¹ is2-chloro-6-fluorophenyl.

1.29 A compound for use according to Embodiment 1.26 wherein Ar¹ is2,6-dichlorophenyl.

1.30 A compound for use in the treatment of T-Cell Acute LymphoblasticLeukaemia (T-ALL), according to Embodiment 1.1, wherein said compound isof the formula (2):

or is a pharmaceutically acceptable salt or stereoisomer thereof;wherein:

R⁷ is selected from chlorine and fluorine;

R³, R⁴, R⁵ and R⁶ are each independently selected from hydrogen,fluorine and chlorine;

n is 0, 1 or 2;

Q¹ is selected from C(═O), S(═O) and SO₂;

A is absent or is NR²;

R¹ is selected from:

-   -   hydrogen;    -   a C₁₋₆ non-aromatic hydrocarbon group optionally substituted        with one or more substituents selected from hydroxyl, C₁₋₂        alkoxy, amino, mono-C₁₋₄ alkylamino, di-C₁₋₄ alkylamino, 3- to        7-membered non-aromatic carbocyclic and heterocyclic rings        containing one or two heteroatom ring members selected from O, N        and S, and bridged bicyclic heterocyclic rings of seven to nine        ring members of which one or two are nitrogen atoms, the        carbocylic and heterocyclic rings and bridged bicyclic        heterocyclic rings being optionally substituted with one or more        hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄ alkanoyl, C₁₋₄        alkanoyloxy, C₁₋₄ alkoxycarbonyl or hydroxyl-C₁₋₃ alkyl groups;        and    -   3- to 7-membered non-aromatic carbocyclic and heterocyclic rings        containing one or two heteroatom ring members selected from O, N        and S, and bridged bicyclic heterocyclic rings of seven to nine        ring members of which one or two are nitrogen atoms, the        carbocyclic and heterocyclic rings and bridged bicyclic        heterocyclic rings being optionally substituted with one or more        hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄ alkanoyl, C₁₋₄        alkanoyloxy, C₁₋₄ alkoxycarbonyl, amino-C₁₋₃alkyl, mono-C₁₋₂        alkylamino-C₁₋₃ alkyl, di-C₁₋₂ alkylamino-C₁₋₃ alkyl or        hydroxyl-C₁₋₃ alkyl groups;

R² is selected from hydrogen and C₁₋₄ alkyl; or

NR¹R² forms a 4- to 7-membered non-aromatic nitrogen-containingheterocyclic ring optionally containing a second heteroatom ring memberselected from nitrogen and oxygen, the heterocyclic ring beingoptionally substituted with one or more hydroxy, C₁₋₄ alkyl, C₁₋₄alkanoyl, C₁₋₄ alkanoyloxy, C₁₋₄ alkoxy, C₁₋₄ alkoxycarbonylamino-C₁₋₃alkyl, mono-C₁₋₂ alkylamino-C₁₋₃ alkyl, di-C₁₋₂alkylamino-C₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl groups; with the provisothat no more than two of R³ to R⁶ are other than hydrogen.

1.31 A compound for use according to Embodiment 1.30 provided that whenR⁷ and R⁶ are both fluorine, then one of R³ to R⁵ is chlorine orfluorine.

1.32 A compound for use according to Embodiment 1.30 or Embodiment 1.31wherein R⁷ is chlorine.

1.33 A compound for use according to Embodiment 1.32 wherein R⁷ ischlorine and R⁶ is fluorine.

1.34 A compound for use according to Embodiment 1.32 wherein R⁷ and R⁶are both chlorine.

1.35 A compound for use according to any one of Embodiments 1.30 to 1.34wherein at least one of R³ and R⁵ is hydrogen.

1.36 A compound for use according to Embodiment 1.35 wherein both of R³and R⁵ are hydrogen.

1.37 A compound according to any one of Embodiments 1.30 to 1.36 whereinR⁴ is hydrogen.

1.38 A compound according to any one of Embodiments 1.30 to 1.36 whereinR⁴ is fluorine.

1.39 A compound according to any one of Embodiments 1.30 to 1.36 whereinR⁴ is chlorine.

1.40 A compound for use according to any one of Embodiments 1.1 to 1.39wherein Q¹ is C(═O).

1.41 A compound for use according to any one of Embodiments 1.1 to 1.39wherein Q¹ is S(═O).

1.42 A compound for use according to any one of Embodiments 1.1 to 1.39wherein Q¹ is SO₂.

1.43 A compound for use according to any one of Embodiments 1.1 to 1.42wherein A is absent (i.e. the moieties R¹ and Q¹ are directly joinedtogether).

1.44 A compound for use according to any one of Embodiments 1.1 to 1.39wherein A is absent and Q¹ is SO₂.

1.45 A compound for use according to any one of Embodiments 1.1 to 1.42wherein A is NR².

1.46 A compound for use according to any one of Embodiments 1.1 to 1.45wherein R¹ is selected from:

-   -   hydrogen;    -   a C₁₋₆ saturated hydrocarbon group optionally substituted with        one or more substituents selected from hydroxy, C₁₋₂ alkoxy,        amino, mono-C₁₋₄ alkylamino, di-C₁₋₄ alkylamino, 3- to        6-membered saturated carbocyclic rings and 4 to 7 membered        heterocyclic rings containing one or two heteroatom ring members        selected from O, N and S, and bridged bicyclic heterocyclic        rings of seven to nine ring members of which one or two are        nitrogen atoms, the carbocylic and heterocyclic rings and        bridged bicyclic heterocyclic rings being optionally substituted        with one or more hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄        alkanoyl, C₁₋₄ alkanoyloxy, C₁₋₄ alkoxycarbonyl, amino-C₁₋₃        alkyl, mono-C₁₋₂ alkylamino-C₁₋₃ alkyl, di-C₁₋₂ alkylamino-C₁₋₃        alkyl or hydroxy-C₁₋₃ alkyl groups; and    -   3- to 6-membered saturated carbocyclic rings and 4 to 7 membered        heterocyclic rings containing one or two heteroatom ring members        selected from O, N and S, and bridged bicyclic heterocyclic        rings of seven to nine ring members of which one or two are        nitrogen atoms, the carbocylic and heterocyclic rings and        bridged bicyclic heterocyclic rings being optionally substituted        with one or more hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄        alkanoyl, C₁₋₄ alkanoyloxy, C₁₋₄ alkoxycarbonyl, amino-C₁₋₃        alkyl, mono-C₁₋₂ alkylamino-C₁₋₃ alkyl, di-C₁₋₂ alkylamino-C₁₋₃        alkyl or hydroxy-C₁₋₃ alkyl groups; R², when present, is        selected from hydrogen and C₁₋₄ alkyl; or NR¹R² forms a 4- to        7-membered saturated nitrogen-containing heterocyclic ring        optionally containing a second heteroatom ring member selected        from nitrogen and oxygen, the heterocyclic ring being optionally        substituted with one or more hydroxy, C₁₋₄ alkyl, C₁₋₄ alkanoyl,        C₁₋₄ alkanoyloxy, C₁₋₄ alkoxy, C₁₋₄ alkoxycarbonyl or        hydroxy-C₁₋₃ alkyl groups.

1.47 A compound for use according to Embodiment 1.46 wherein R¹ isselected from:

-   -   hydrogen;    -   a C₁₋₄ alkyl group optionally substituted with one or more        substituents selected from hydroxyl, C₁₋₃ alkoxy, amino,        mono-C₁₋₃ alkylamino, di-C₁₋₃ alkylamino, 3- to 5-membered        saturated carbocyclic rings and 4- to 6-membered heterocyclic        rings containing one or two heteroatom ring members selected        from O, N and S, the carbocylic and heterocyclic rings being        optionally substituted with one or more hydroxy, C₁₋₃ alkyl,        C₁₋₃ alkoxy, C₁₋₃ alkanoyl, C₁₋₃ alkanoyloxy, C₁₋₃        alkoxycarbonyl, or hydroxy-C₁₋₃ alkyl groups; and    -   3- to 5-membered saturated carbocyclic rings and 4 to 6 membered        heterocyclic rings containing one or two heteroatom ring members        selected from O, N and S, the carbocylic and heterocyclic rings        being optionally substituted with one or more hydroxy, C₁₋₃        alkyl, C₁₋₃ alkoxy, C₁₋₃ alkanoyl, C₁₋₃ alkanoyloxy, C₁₋₄        alkoxycarbonyl or hydroxy-C₁₋₃ alkyl groups;

R², when present, is selected from hydrogen and C₁₋₂ alkyl; or

NR¹R² forms a 4- to 7-membered saturated nitrogen-containingheterocyclic ring optionally containing a second heteroatom ring memberselected from nitrogen and oxygen, the heterocyclic ring beingoptionally substituted with one or more hydroxy, C₁₋₃ alkyl, C₁₋₃alkanoyl, C₁₋₃ alkanoyloxy, C₁₋₃ alkoxy, C₁₋₄ alkoxycarbonyl orhydroxy-C₁₋₃ alkyl groups.

1.48 A compound for use according to Embodiment 1.46 wherein R¹ isselected from:

-   -   hydrogen;    -   a C₁₋₄ alkyl group optionally substituted with one or more        substituents selected from hydroxy, amino, mono-C₁₋₃ alkylamino        and di-C₁₋₃ alkylamino; and    -   5 to 6-membered heterocyclic rings containing a nitrogen ring        member and optionally a second ring member selected from N and        O, the heterocyclic rings being optionally substituted with one        or more C₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl groups;

R², when present, is selected from hydrogen and C₁₋₂ alkyl; or

NR¹R² forms a 5 to 6-membered heterocyclic ring containing a nitrogenring member and optionally a second ring member selected from N and O,the heterocyclic rings being optionally substituted with one or moreC₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl groups.

1.49 A compound for use according to Embodiment 1.46 wherein R¹ isselected from:

-   -   hydrogen;    -   a C₁₋₄ alkyl group optionally substituted with one or more        substituents selected from hydroxy, amino and mono-C₁₋₃        alkylamino; and    -   5 to 6-membered heterocyclic rings selected from pyrrolidine,        piperidine, piperazine and morpholine, the heterocyclic rings        being optionally substituted with one or more C₁₋₃ alkyl or        hydroxy-C₁₋₃ alkyl groups;

R², when present, is selected from hydrogen and C₁₋₂ alkyl; or

NR¹R² forms a 5 to 6-membered heterocyclic ring selected frompyrrolidine, piperidine, piperazine and morpholine, the heterocyclicring being optionally substituted with one or more C₁₋₃ alkyl orhydroxy-C₁₋₃ alkyl groups.

1.50 A compound for use according to Embodiment 1.46 wherein R¹ isselected from:

-   -   hydrogen;    -   a C₁₋₃ alkyl group optionally substituted with one or more        substituents selected from hydroxy, amino and methylamino; and    -   5 to 6-membered heterocyclic rings selected from pyrrolidine,        piperidine, piperazine and morpholine, the heterocyclic rings        being optionally substituted with one or more C₁₋₃ alkyl or        hydroxy-C₁₋₃ alkyl groups;

R², when present, is selected from hydrogen and C₁₋₂ alkyl; or

NR¹R² forms a 5 to 6-membered heterocyclic ring selected frompyrrolidine, piperidine, piperazine and morpholine, the heterocyclicring being optionally substituted with one or more C₁₋₃ alkyl orhydroxy-C₁₋₃ alkyl groups.

1.51 A compound for use according to Embodiment 1.46 wherein R¹ isselected from:

-   -   hydrogen;    -   a C₁₋₃ alkyl group optionally substituted with one or more        substituents selected from hydroxy, amino and methylamino; and    -   5 to 6-membered heterocyclic rings selected from pyrrolidine and        piperidine, the heterocyclic rings being optionally substituted        with a methyl group;

R², when present, is selected from hydrogen and methyl; or

NR¹R² forms a 5 to 6-membered heterocyclic ring selected frompyrrolidine and morpholine, the heterocyclic ring being optionallysubstituted with a hydroxymethyl group.

1.52 A compound according to any one of Embodiments 1.1 to 1.45 whereinR¹ is selected from:

-   -   hydrogen; and    -   a C₁₋₆ non-aromatic hydrocarbon group optionally substituted        with one or more substituents selected from hydroxyl, C₁₋₂        alkoxy, amino, mono-C₁₋₄ alkylamino, di-C₁₋₄ alkylamino, 3- to        7-membered non-aromatic carbocyclic and heterocyclic rings        containing one or two heteroatom ring members selected from O, N        and S, and bridged bicyclic heterocyclic rings of seven to nine        ring members of which one or two are nitrogen atoms, the        carbocylic and heterocyclic rings and bridged bicyclic        heterocyclic rings being optionally substituted with one or more        hydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄ alkanoyl, C₁₋₄        alkanoyloxy, C₁₋₄ alkoxycarbonyl or hydroxyl-C₁₋₃ alkyl groups.

1.53 A compound according to any one of Embodiments 1.1 to 1.45 whereinR¹ is selected from:

-   -   hydrogen; and    -   a C₁₋₄ alkyl group optionally substituted with one or more        substituents selected from hydroxyl, C₁₋₃ alkoxy, amino,        mono-C₁₋₃ alkylamino, di-C₁₋₃ alkylamino, 3- to 5-membered        saturated carbocyclic rings and 4- to 6-membered heterocyclic        rings containing one or two heteroatom ring members selected        from O, N and S, the carbocylic and heterocyclic rings being        optionally substituted with one or more hydroxy, C₁₋₃ alkyl,        C₁₋₃ alkoxy, C₁₋₃ alkanoyl, C₁₋₃ alkanoyloxy, C₁₋₃        alkoxycarbonyl, or hydroxy-C₁₋₃ alkyl groups.

1.54 A compound according to any one of Embodiments 1.1 to 1.45 whereinR¹ is selected from:

-   -   hydrogen; and    -   a C₁₋₄ alkyl group optionally substituted with one or more        substituents selected from hydroxy, amino, mono-C₁₋₃ alkylamino        and di-C₁₋₃ alkylamino.

1.55 A compound according to any one of Embodiments 1.1 to 1.45 whereinR¹ is selected from:

-   -   hydrogen;    -   a C₁₋₄ alkyl group optionally substituted with one or more        substituents selected from hydroxy, amino and mono-C₁₋₃        alkylamino; and    -   5 to 6-membered non-aromatic heterocyclic rings containing a        nitrogen ring member and optionally a second ring member        selected from N and O, the heterocyclic rings being optionally        substituted with one or more C₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl        groups.

1.56 A compound according to any one of Embodiments 1.1 to 1.45 whereinR¹ is selected from:

-   -   hydrogen; and    -   a C₁₋₃ alkyl group optionally substituted with one or more        substituents selected from hydroxy, amino and methylamino.

1.57 A compound according to Embodiment 1.56 wherein R¹ is a C₁₋₃ alkylgroup.

1.58 A compound according to Embodiment 1.57 wherein R¹ is selected frommethyl, ethyl and isopropyl.

1.59 A compound according to Embodiment 1.58 wherein R¹ is methyl.

1.60 A compound according to Embodiment 1.58 wherein R¹ is ethyl.

1.61 A compound according to Embodiment 1.58 wherein R¹ is isopropyl.

1.62 A compound according to Embodiment 1.56 wherein R¹ is a C₁₋₃ alkylgroup optionally substituted with one or more substituents selected fromhydroxy, amino and methylamino.

1.63 A compound according to Embodiment 1.62 wherein R¹ is a C₂₋₃ alkylgroup substituted with one or more substituents selected from hydroxy,amino and methylamino.

1.64 A compound according to Embodiment 1.63 wherein R¹ is selected from3-aminopropyl, 3-methylaminopropyl, 2-methylaminoethyl, 3-hydroxypropyland 2-hydroxyethyl.

1.65 A compound according to Embodiment 1.56 wherein R¹ is hydrogen.

1.66 A compound for use according to any one of Embodiments 1.1 to 1.45wherein R¹ is selected from 3- to 6-membered saturated carbocyclic ringsand 4 to 7 membered heterocyclic rings containing one or two heteroatomring members selected from O, N and S, and bridged bicyclic heterocyclicrings of seven to nine ring members of which one or two are nitrogenatoms, the carbocylic and heterocyclic rings and bridged bicyclicheterocyclic rings being optionally substituted with one or morehydroxy, C₁₋₄ alkyl, C₁₋₄ alkoxy, C₁₋₄ alkanoyl, C₁₋₄ alkanoyloxy, C₁₋₄alkoxycarbonyl, amino-C₁₋₃ alkyl, mono-C₁₋₂ alkylamino-C₁₋₃ alkyl,di-C₁₋₂ alkylamino-C₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl groups.

1.67 A compound for use according to any one of Embodiments 1.1 to 1.45wherein R¹ is selected from 3- to 5-membered saturated carbocyclic ringsand 4 to 6 membered non-aromatic heterocyclic rings containing one ortwo heteroatom ring members selected from O, N and S, the carbocylic andheterocyclic rings being optionally substituted with one or morehydroxy, C₁₋₃ alkyl, C₁₋₃ alkoxy, C₁₋₃ alkanoyl, C₁₋₃ alkanoyloxy, C₁₋₄alkoxycarbonyl or hydroxy-C₁₋₃ alkyl groups.

1.68 A compound for use according to any one of Embodiments 1.1 to 1.45wherein R¹ is selected from 5 to 6-membered non-aromatic heterocyclicrings containing a nitrogen ring member and optionally a second ringmember selected from N and O, the heterocyclic rings being optionallysubstituted with one or more C₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl groups.

1.69 A compound for use according to any one of Embodiments 1.1 to 1.45wherein R¹ is a 5- or 6-membered non-aromatic heterocyclic ring selectedfrom pyrrolidine, piperidine, piperazine and morpholine, theheterocyclic ring being optionally substituted with one or more C₁₋₃alkyl or hydroxy-C₁₋₃ alkyl groups.

1.70 A compound according to Embodiment 1.69 wherein R¹ is a 5 to6-membered heterocyclic ring selected from pyrrolidine and piperidine,the heterocyclic ring being optionally substituted with a methyl group.

1.71 A compound for use according to any one of Embodiments 1.1 to 1.42wherein A is NR² and NR¹R² forms a 4- to 7-membered saturatednitrogen-containing heterocyclic ring optionally containing a secondheteroatom ring member selected from nitrogen and oxygen, theheterocyclic ring being optionally substituted with one or more hydroxy,C₁₋₄ alkyl, C₁₋₄ alkanoyl, C₁₋₄ alkanoyloxy, C₁₋₄ alkoxy, C₁₋₄alkoxycarbonyl or hydroxy-C₁₋₃ alkyl groups.

1.72 A compound for use according to any one of Embodiments 1.1 to 1.42wherein A is NR² and NR¹R² forms a 4- to 7-membered saturatednitrogen-containing heterocyclic ring optionally containing a secondheteroatom ring member selected from nitrogen and oxygen, theheterocyclic ring being optionally substituted with one or more hydroxy,C₁₋₃ alkyl, C₁₋₃ alkanoyl, C₁₋₃ alkanoyloxy, C₁₋₃ alkoxy, C₁₋₄alkoxycarbonyl or hydroxy-C₁₋₃ alkyl groups.

1.73 A compound for use according to any one of Embodiments 1.1 to 1.42wherein A is NR² and NR¹R² forms a 5 to 6-membered heterocyclic ringcontaining a nitrogen ring member and optionally a second ring memberselected from N and O, the heterocyclic rings being optionallysubstituted with one or more C₁₋₃ alkyl or hydroxy-C₁₋₃ alkyl groups.

1.74 A compound for use according to any one of Embodiments 1.1 to 1.42wherein A is NR² and NR¹R² forms a 5 to 6-membered heterocyclic ringselected from pyrrolidine, piperidine, piperazine and morpholine, theheterocyclic ring being optionally substituted with one or more C₁₋₃alkyl or hydroxy-C₁₋₃ alkyl groups.

1.75 A compound for use according to any one of Embodiments 1.1 to 1.42wherein A is NR² and NR¹R² forms a 5 to 6-membered heterocyclic ringselected from pyrrolidine and morpholine, the heterocyclic ring beingoptionally substituted with a hydroxymethyl group.

1.76 A compound for use according to any one of Embodiments 1.1 to 1.42wherein R² is selected from hydrogen and methyl.

1.77 A compound for use according to any one of Embodiments 1.1 to 1.42and 1.45 wherein R² is hydrogen.

1.78 A compound for use according to any one of Embodiments 1.1 to 1.42and 1.45 wherein R² is methyl.

1.79 A compound for use according to any one of Embodiments 1.1 to 1.39wherein Q¹-A-R¹ is selected from groups AA to AT in the table below:

wherein the point of attachment to the phenyl group is indicated by theasterisk.

1.80 A compound according to Embodiment 1.79 wherein Q¹-A-R¹ is selectedfrom groups AA, AG, AH, AI, AR, AS and AT.

1.81 A compound according to Embodiment 1.80 wherein Q¹-A-R¹ is selectedfrom groups AA, AG, AH, AI and AR.

1.82 A compound for use according to Embodiment 1.81 wherein Q¹-A-R¹ isthe group AA or AI.

1.83 A compound for use according to Embodiment 1.81 wherein Q¹-A-R¹ isthe group AI.

1.84 A compound for use according to Embodiment 1.1 wherein the compoundof formula (1) is selected from:

-   2-(2,6-dichloro-phenyl)-5-(4-methanesulfonyl-phenylamino)-oxazole-4-carboxylic    acid amide;-   2-(2-chloro-6-fluoro-phenyl)-5-(4-methanesulfonyl-phenylamino)-oxazole-4-carboxylic    acid amide;-   5-(4-methanesulfonyl-phenylamino)-2-(2,4,6-trifluoro-phenyl)-oxazole-4-carboxylic    acid amide;-   2-(2,5-difluoro-phenyl)-5-(4-methanesulfonyl-phenylamino)-oxazole-4-carboxylic    acid amide;-   (S)    2-(2-chloro-6-fluoro-phenyl)-5-[4-(piperidin-3-ylcarbamoyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   (R)    2-(2-chloro-6-fluoro-phenyl)-5-[4-(piperidin-3-ylcarbamoyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   2-(2-chloro-6-fluoro-phenyl)-5-[4-(morpholine-4-carbonyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   2-(2-chloro-6-fluoro-phenyl)-5-[4-(1-methyl-piperidin-4-ylcarbamoyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   (S)    2-(2,6-dichloro-phenyl)-5-[4-(piperidin-3-ylcarbamoyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   (R)    2-(2,6-dichloro-phenyl)-5-[4-(piperidin-3-ylcarbamoyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   2-(2,6-dichloro-phenyl)-5-[4-(morpholine-4-carbonyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   2-(2,6-dichloro-phenyl)-5-[4-(1-methyl-piperidin-4-ylcarbamoyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   2-(2,6-difluoro-phenyl)-5-(4-ethanesulfonyl-phenylamino)-oxazole-4-carboxylic    acid amide;-   2-(2,6-difluoro-phenyl)-5-(4-methanesulfonyl-phenylamino)-oxazole-4-carboxylic    acid amide; and-   2-(2,6-difluoro-phenyl)-5-[4-propane-2-sulfonyl)-phenylamino]-oxazole-4-carboxylic    acid amide;-   2-(2,6-Dichloro-phenyl)-5-(4-methanesulfonyl-phenylamino)-oxazole-4-carboxylic    acid amide;-   2-(2-Chloro-6-fluoro-phenyl)-5-(4-methanesulfonyl-phenylamino)-oxazole-4-carboxylic    acid amide;-   2-(2-Chloro-6-fluoro-phenyl)-5-[4-(morpholine-4-carbonyl)-phenylamino]-oxazole-4-carboxylic    acid amide; and-   2-(2,6-Dichloro-phenyl)-5-[4-(morpholine-4-carbonyl)-phenylamino]-oxazole-4-carboxylic    acid amide.

1.85 A compound for use according to any one of Embodiments 1.1 to 1.84wherein the compound of formula (1) or formula (2) is in the form of asalt.

1.86 A compound for use according to Embodiment 1.85 wherein the salt isan acid addition salt.

1.87 A compound for use according to Embodiment 1.85 or Embodiment 1.86wherein the salt is a pharmaceutically acceptable salt.

1.88 A compound for use according to any one of Embodiments 1.1 to 1.84wherein the compound of formula (1) or formula (2) is in the form of afree base.

Definitions

The term “non-aromatic hydrocarbon group”, as in “C₁₋₆ non-aromatichydrocarbon group”, as used herein refers to a structural groupconsisting of carbon and hydrogen and which does not have aromaticcharacter.

Unless indicated otherwise, the non-aromatic hydrocarbon group can beacyclic or cyclic and can be saturated or unsaturated. Thus the termcovers alkyl, alkenyl, alkynyl, cycloalkyl and cycloalkenyl groups andcombinations thereof.

Where specified, non-aromatic hydrocarbon groups can be substituted;i.e. a hydrogen atom may be replaced by another atom or functionalgroup.

References to “non-aromatic carbocyclic and heterocyclic rings” as usedherein refer to both saturated and unsaturated ring systems providedthat any such unsaturated ring systems do not have aromatic character,

The term “bridged bicyclic heterocyclic rings” as used herein refers tonon-aromatic heterocyclic ring systems in which two rings share morethan two atoms, see for example Advanced Organic Chemistry, by JerryMarch, 4th Edition, Wiley Interscience, pages 131-133, 1992. The bridgedbicyclic ring systems can be, for example, [3.2.1] bicyclic ring systemssuch as an 8-aza-bicyclo[3.2.1]octane-3-yl group, or [2.2.2] bicyclicring systems such as a quinuclidin-3-yl group.

Salts

The compounds of formula (1) or formula (2) may be presented in the formof salts.

The salts (as defined in Embodiments 1.85 to 1.87) are typically acidaddition salts.

The salts can be synthesized from the parent compound by conventionalchemical methods such as methods described in Pharmaceutical Salts:Properties, Selection, and Use, P. Heinrich Stahl (Editor), Camille G.Wermuth (Editor), ISBN: 3-90639-026-8, Hardcover, 388 pages, August2002. Generally, such salts can be prepared by reacting the free baseform of the compound with the acid in water or in an organic solvent, orin a mixture of the two; generally, nonaqueous media such as ether,ethyl acetate, ethanol, isopropanol, or acetonitrile are used.

Acid addition salts (as defined in Embodiment 1.86) may be formed with awide variety of acids, both inorganic and organic. Examples of acidaddition salts include salts formed with an acid selected from the groupconsisting of acetic, 2,2-dichloroacetic, adipic, alginic, ascorbic(e.g. L-ascorbic), L-aspartic, benzenesulphonic, benzoic,4-acetamidobenzoic, butanoic, (+) camphoric, camphor-sulphonic,(+)-(1S)-camphor-10-sulphonic, capric, caproic, caprylic, cinnamic,citric, cyclamic, dodecylsulphuric, ethane-1,2-disulphonic,ethanesulphonic, 2-hydroxyethanesulphonic, formic, fumaric, galactaric,gentisic, glucoheptonic, D-gluconic, glucuronic (e.g. D-glucuronic),glutamic (e.g. L-glutamic), α-oxoglutaric, glycolic, hippuric,hydrobromic, hydrochloric, hydriodic, isethionic, (+)-L-lactic,(±)-DL-lactic, lactobionic, maleic, malic, (−)-L-malic, malonic,(±)-DL-mandelic, methanesulphonic, naphthalene-2-sulphonic,naphthalene-1,5-disulphonic, 1-hydroxy-2-naphthoic, nicotinic, nitric,oleic, orotic, oxalic, palmitic, pamoic, phosphoric, propionic,L-pyroglutamic, salicylic, 4-amino-salicylic, sebacic, stearic,succinic, sulphuric, tannic, (+)-L-tartaric, thiocyanic,p-toluenesulphonic, undecylenic and valeric acids, as well as acylatedamino acids and cation exchange resins.

The salt forms of the compounds of the invention are typicallypharmaceutically acceptable salts, and examples of pharmaceuticallyacceptable salts are discussed in Berge et al., 1977, “PharmaceuticallyAcceptable Salts,” J. Pharm. Sci., Vol. 66, pp. 1-19.

However, salts that are not pharmaceutically acceptable may also beprepared as intermediate forms which may then be converted intopharmaceutically acceptable salts.

Such non-pharmaceutically acceptable salts forms, which may be useful,for example, in the purification or separation of the compounds of theinvention, also form part of the invention.

Isotopes

The compounds for use according to the invention as defined in any oneof Embodiments 1.1 to 1.88 may contain one or more isotopicsubstitutions, and a reference to a particular element includes withinits scope all isotopes of the element. For example, a reference tohydrogen includes within its scope ¹H, ²H (D), and ³H (T). Similarly,references to carbon and oxygen include within their scope respectively¹²C, ¹³C and ¹⁴C and ¹⁶O and ¹⁸O In an analogous manner, a reference toa particular functional group also includes within its scope isotopicvariations, unless the context indicates otherwise.

For example, a reference to an alkyl group such as an ethyl group alsocovers variations in which one or more of the hydrogen atoms in thegroup is in the form of a deuterium or tritium isotope, e.g. as in anethyl group in which all five hydrogen atoms are in the deuteriumisotopic form (a perdeuteroethyl group).

The isotopes may be radioactive or non-radioactive. In one embodiment ofthe invention (Embodiment 1.89), the compound for use according to anyone of Embodiments 1.1 to 1.88 contains no radioactive isotopes. Suchcompounds are preferred for therapeutic use. In another embodiment(Embodiment 1.90), however, the compound of any one of Embodiments 1.1to 1.88 may contain one or more radioisotopes. Compounds containing suchradioisotopes may be useful in a diagnostic context.

Solvates

Compounds for use as defined in any one of Embodiments 1.1 to 1.90 mayform solvates.

Preferred solvates are solvates formed by the incorporation into thesolid state structure (e.g. crystal structure) of the compounds of theinvention of molecules of a non-toxic pharmaceutically acceptablesolvent (referred to below as the solvating solvent).

Examples of such solvents include water, alcohols (such as ethanol,isopropanol and butanol) and dimethylsulphoxide. Solvates can beprepared by recrystallizing the compounds of the invention with asolvent or mixture of solvents containing the solvating solvent. Whetheror not a solvate has been formed in any given instance can be determinedby subjecting crystals of the compound to analysis using well known andstandard techniques such as thermogravimetric analysis (TGE),differential scanning calorimetry (DSC) and X-ray crystallography.

The solvates can be stoichiometric or non-stoichiometric solvates.

Particularly preferred solvates are hydrates, and examples of hydratesinclude hemihydrates, monohydrates and dihydrates.

Accordingly, in further embodiments 1.91 and 1.92, the inventionprovides:

1.91 A compound for use according to any one of Embodiments 1.1 to 1.90wherein the compound is in the form of a solvate.

1.92 A compound for use according to Embodiment 1.91 wherein the solvateis a hydrate.

For a more detailed discussion of solvates and the methods used to makeand characterise them, see Bryn et al., Solid-State Chemistry of Drugs,Second Edition, published by SSCI, Inc of West Lafayette, Ind., USA,1999, ISBN 0-967-06710-3.

Alternatively, rather than existing as a hydrate, the compound of theinvention may be anhydrous. Therefore, in another embodiment (Embodiment1.93), the compound for use as defined in any one of Embodiments 1.1 to1.90 is in an anhydrous form.

Biological Activity

Compounds of the formulae (1) and (2) as defined in Embodiments 1.1 to1.93 are inhibitors of TYK2 kinase. The TYK2 kinase-inhibitingactivities of the compounds can be determined using the assays describedin the Examples below. Particular compounds of formulae (1) and (2) foruse in accordance with the invention are compounds having IC₅₀ valuesagainst TYK2 kinase in the assay described in Example 1 below of lessthan 50 nanomolar.

Compounds of the formulae (1) and (2) as defined in Embodiments 1.1 to1.93 have been found to have activity against certain types of cancersin which TYK2 kinase is implicated. The cancers may be cancers in whichTYK2 is required for survival; e.g. cancers in which a TYK2-STAT1-BCL2pathway exists to prevent apoptosis of the cancer cells. Examples ofsuch cancers include certain T-ALL cancers as described below in theexperimental section of this application.

In addition to being active against TYK2-dependent T-ALL cells, it hasalso been found that compounds of formulae (1) and (2) as defined inEmbodiments 1.1 to 1.93 have activity against certain TYK2-independentcancer cells, such as the LOUCY cell line as described below in theexperimental section of this application. The basis for the activityagainst TYK2-independent T-ALL cell lines is currently uncertain butsuggests that the compounds of formulae (1) and (2) will be useful intreating a wider range of T-ALL cancers than, for example, the JAKkinase inhibitors discussed in Sanda et al. (idem).

Accordingly, the invention also provides methods of treating cancers anduses of the compounds of formulae (1) and (2) as set out in Embodiments2.1 to 2.13 below.

2.1 A compound of the formula (1) or (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment of a TYK2-dependent T-Cell AcuteLymphoblastic Leukaemia.

2.2 A compound of the formula (1) or (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment of a TYK2-independent T-Cell AcuteLymphoblastic Leukaemia.

2.3 The use of a compound of the formula (1) or (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment of a T-Cell Acute Lymphoblastic Leukaemia.

2.4 The use according to Embodiment 2.3 wherein the T-Cell AcuteLymphoblastic Leukaemia is selected from TYK2-dependent T-ALL andTYK2-independent T-ALL tumour types.

2.5 The use according to Embodiment 2.4 wherein the T-Cell AcuteLymphoblastic Leukaemia is selected from TYK2-dependent T-ALL tumourtypes.

2.6 The use according to Embodiment 2.4 wherein the T-Cell AcuteLymphoblastic Leukaemia is selected from TYK2-independent T-ALL tumourtypes.

2.7 A method of treating T-Cell Acute Lymphoblastic Leukaemia, whichmethod comprises administering to a subject in need thereof atherapeutically effective amount of a compound of the formula (1) or(2), or a pharmaceutically acceptable salt thereof, as defined in anyone of Embodiments 1.1 to 1.93.

2.8 A method according to Embodiment 2.7 wherein the T-Cell AcuteLymphoblastic Leukaemia is selected from TYK2-dependent T-ALL andTYK2-independent T-ALL tumour types.

2.9 A method according to Embodiment 2.8 wherein the T-Cell AcuteLymphoblastic Leukaemia is selected from TYK2-dependent T-ALL tumourtypes.

2.10 A method according to Embodiment 2.8 wherein the T-Cell AcuteLymphoblastic Leukaemia is selected from TYK2-independent T-ALL tumourtypes.

2.11 A compound of the formula (1) or (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment of a cancer in a patient who has beentested and diagnosed as being susceptible to treatment with a TYK2inhibitor.

2.12 The use of a compound of the formula (1) or (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment of a cancer in a patient who has been tested and diagnosed asbeing susceptible to treatment with a TYK2 inhibitor.

2.13 A method of treating a cancer in a patient who has been tested anddiagnosed as being susceptible to treatment with a TYK2 inhibitor, whichmethod comprises administering to the patient a therapeuticallyeffective amount of a compound of the formula (1) or (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93.

The STAT (Signal Transducers and Activators of Transcription) family oftranscription factors are downstream effectors of TYK2 kinase in theJAK/STAT cytokine signalling pathways, for example in the interleukin(IL)-10 pathway. Phosphorylation of STAT1 is seen in a number of T-ALLcell lines and many of these are TYK2 dependent (Sanda et al.“TYK2-STAT1-BCL2 Pathway Dependence in T-cell Acute LymphoblasticLeukemia”, (2013), Cancer Discov., 3(5), pp 564-577.) Aberrantactivation of the TYK2-STAT1 pathway upregulates the anti-apoptoticprotein, BCL2, which is required for T-ALL cells to survive.

STAT3 is frequently correlated to tumorigenesis, and is considered as anoncogene (see Pensa et al., 2009 Landes Bioscience). In particular,STAT3 constitutive activity has been reported in nearly 70% of solid andhematological tumours, including multiple myeloma, several lymphomas andleukemias, breast cancer, head and neck cancer, prostate cancer, ovariancarcinoma, melanoma, renal carcinoma, colorectal carcinoma and thymicepithelial tumours (Kortylewski et al. Targeting STAT3 affects melanomaon multiple fronts. Cancer Metastasis Rev. 2005; 24(2): 315-327)).

STAT5 proteins are activated by a wide variety of hematopoietic andnonhematopoietic cytokines and growth factors, all of which use theJAK-STAT signalling pathway as their main mode of signal transduction.STAT5 proteins critically regulate vital cellular functions such asproliferation, differentiation, and survival. The physiologicalimportance of STAT5 proteins can be seen from the number of primaryhuman tumours that have aberrant constitutive activation of theseproteins, which significantly contributes to tumour cell survival andmalignant progression of disease (Rani et al., J. Interferon CytokineRes. 2016 April; 36(4): 226-37. doi: 10.1089/jir.2015.0054. Epub 2015Dec. 30).

Therefore, it is envisaged that the compounds of formulae (1) and (2)and their pharmaceutically acceptable salts may be useful in treatingcancers which are characterised by abnormally elevated levels ofphosphorylated STAT proteins and particularly STAT1, STAT3 and STAT5and/or abnormally elevated levels of BCL2. Accordingly, in Embodiments2.8 to 2.13 the invention provides:

2.14 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one Embodiments 1.1 to 1.93for use in the treatment or prophylaxis of a cancer characterised byabnormally elevated levels of any one or more of phosphorylated STAT1,phosphorylated STAT3 and phosphorylated STAT5.

2.15 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any oneEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment or prophylaxis of a cancer characterised by abnormallyelevated levels of any one or more of phosphorylated STAT1,phosphorylated STAT3 and phosphorylated STAT5.

2.16 A method for the treatment or prophylaxis of a cancer characterisedby abnormally elevated levels of any one or more of phosphorylatedSTAT1, phosphorylated STAT3 and phosphorylated STAT5, which methodcomprises administering to a patient, optionally in combination withradiotherapy, a therapeutically effective amount of a compound offormula (1) or formula (2), or a pharmaceutically acceptable saltthereof, as defined in any one Embodiments 1.1 to 1.93.

2.17 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one Embodiments 1.1 to 1.93for use in the treatment or prophylaxis of a cancer characterised byabnormally elevated levels of BCL2.

2.18 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any oneEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment or prophylaxis of a cancer characterised by abnormallyelevated levels of BCL2.

2.19 A method for the treatment or prophylaxis of a cancer characterisedby abnormally elevated levels of BCL2, which method comprisesadministering to a patient a therapeutically effective amount of acompound of formula (1) or formula (2), or a pharmaceutically acceptablesalt thereof, as defined in any one Embodiments 1.1 to 1.93.

2.20 A compound formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one Embodiments 1.1 to 1.93for use in alleviating or reducing the incidence of a cancercharacterised by abnormally elevated levels of any one or more ofphosphorylated STAT1, phosphorylated STAT3 and phosphorylated STAT5and/or BCL2.

2.21 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any oneEmbodiments 1.1 to 1.93 for the manufacture of a medicament foralleviating or reducing the incidence of a cancer characterised byabnormally elevated levels of any one or more of phosphorylated STAT1,phosphorylated STAT3 and phosphorylated STAT5 and/or BCL2.

2.22 A method of alleviating or reducing the incidence of a cancercharacterised by abnormally elevated levels of any one or more ofphosphorylated STAT1, phosphorylated STAT3 and phosphorylated STAT5and/or BCL2 in a subject (e.g. a mammalian subject, such as a human, inneed thereof), which method comprises administering to the subject atherapeutically effective amount of compound of formula (1) or formula(2), or a pharmaceutically acceptable salt thereof, as defined in anyone Embodiments 1.1 to 1.93.

Compounds of the invention may also be useful in treating cancers thatare characterised by aberrant TYK2 kinase activation. TYK2 genomicrearrangements have been identified in studies through wholegenome/transcriptome analysis of patients diagnosed with mature T-cellneoplasms or acute lymphoblastic leukaemia. A fusion of the 5′ region ofnucleophosmin gene (NPM1) with the 3′ region of TYK2, including a partof the pseudokinase and the complete kinase domain, was revealed by RNAsequencing of a cutaneous T-cell lymphoma-derived cell line. Examinationof a large cohort of mature T-cell lymphoproliferative disordersrevealed TYK2 rearrangements in 15% of CD30+ lymphoproliferativedisorders, including 12.5% of patients with primary anaplastic largecell lymphoma. Detailed analysis of the NPM1-TYK2 fusion proteinrevealed a constitutive TYK2 activation as revealed by Y1054/Y1055phosphorylation, which in turn was shown, by phosphorylation of theappropriate tyrosine residues to lead to constitutively activateddownstream effectors STAT1, STAT3 and STAT5.

Additional TYK2 fusion proteins have been reported in patients diagnosedwith anaplastic large cell lymphoma. In one case the coding region ofexons 1-8 of poly(A) binding protein cytoplasmic 4 (PABPC4) was fused toexons 14-23 of TYK2 (PABPC4-TYK2). In another case, a fusion of exons1-16 of nuclear factor of kappa light polypeptide gene enhancer in Bcells 2 (NFKB2) to exons 16-23 of TYK2 (NFKB2-TYK2) was observed.Ectopic expression of NFKB2-TYK2 in a HEK293 cell line led toconstitutive phosphorylation of TYK2, JAK2 and STAT3, which did notoccur when using a kinase-dead version of NFKB2-TYK2. It was shown thatthe fusion protein had oncogenic activity by transfecting NFKB2-TYK2into mouse 3T3 fibroblasts, resulting in a larger number of coloniesthan in control cells.

Whether a particular cancer is of a type described above may bedetermined by analysing the cancer for the presence of one of the saidfusion proteins.

Thus, in further embodiments (Embodiments 2.23 to 2.37, the inventionprovides:

2.23 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in treating, or alleviating or reducing the incidence of, acancer characterised by aberrant TYK2 kinase activation.

2.24 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in treating, or alleviating or reducing the incidence of, acancer characterised by aberrant TYK2 kinase activation associated witha TYK2 genomic rearrangement.

2.25 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in treating, or alleviating or reducing the incidence of, acancer characterised by aberrant TYK2 kinase activation associated withfusion of a region of the TYK2 gene with another gene.

2.26 A compound for use according to Embodiment 2.25 wherein the fusionis at the 3′ region of TYK2.

2.27 A compound for use according to Embodiment 2.26 wherein the fusioncomprises a fusion of the 5′ region of nucleophosmin gene (NPM1) withthe 3′ region of TYK2.

2.28 A compound for use according to Embodiment 2.25 wherein the fusionis a fusion to the exons 14-23 of TYK2.

2.29 A compound for use according to Embodiment 2.28 wherein the fusioncomprises the fusion of coding region of exons 1-8 of poly(A) bindingprotein cytoplasmic 4 (PABPC4) to exons 14-23 of TYK2 (PABPC4-TYK2).

2.30 A compound for use according to Embodiment 2.25 wherein the fusionis a fusion to exons 16-23 of TYK2.

2.31 A compound for use according to Embodiment 2.30 wherein the fusioncomprises a fusion of exons 1-16 of nuclear factor of kappa lightpolypeptide gene enhancer in B cells 2 (NFKB2) to exons 16-23 of TYK2(NFKB2-TYK2).

2.32 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in alleviating or reducing the incidence of a cancercharacterised by the presence of a fusion protein arising from thefusions of any one of Embodiments 2.25 to 2.31.

2.33 A compound for use according to Embodiment 2.32 wherein the fusionprotein is a NPM1-TYK2 fusion protein.

2.34 A compound for use according to Embodiment 2.32 wherein the fusionprotein is a PABPC4-TYK2 fusion protein.

2.35 A compound for use according to Embodiment 2.32 wherein the fusionprotein is a NFKB2-TYK2 fusion protein.

2.36 The use of a compound of the formula (1) or (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for a use asdefined in any one of Embodiments 2.23 to 2.35.

2.37 A method of treating a cancer in a subject (e.g. a mammaliansubject such as a human), wherein the cancer is as defined in any one ofEmbodiments 2.23 to 2.35, which method comprises administering to thesubject a therapeutically effective amount of a compound of formula (1)or (2), or a pharmaceutically acceptable salt thereof, as defined in anyone of Embodiments 1.1 to 1.93.

In another general embodiment, the cancers may be such that normal TYK2activity contributes to the hallmarks and enabling characteristics ofcancer. An example of a cell extrinsic effect is the requirement of TYK2activity in the induction of angiogenesis.

Angiogenesis, the generation of new blood vessels, is essential toprovide a growing tumour with nutrients and oxygen. The urokinase typeplasminogen activator (uPA) and its receptor uPAR have been shown toplay an important role in angiogenesis, and furthermore, that TYK2 isessential in mediating the uPA-uPAR induced signalling in vascularsmooth muscle cells and glomerular mesangial cells. An example of a cellintrinsic effect, is the contribution of TYK2 toepithelial-to-mesenchymal transition (EMT), a crucial processfacilitating tumour cell invasion and dissemination, DuringEMT/metastasis, Annexin A1 is frequently down-regulated and knockdown ofAnnexin A1 induces EMT in a TYK2 dependent manner. In an Ep-Myctransgenic mouse model for human Burkitt's lymphoma, TYK2-deficient miceshowed reduced invasiveness of malignant cells.

Accordingly, in further embodiments, the invention provides:

2.38 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in treating, or alleviating or reducing the incidence of, acancer characterised by normal expression of TYK2 kinase (e.g. whereinthe TYK2 kinase contains no detectable markers of aberrant expression).

2.39 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament fortreating, or alleviating or reducing the incidence of, a cancercharacterised by normal expression of TYK2 kinase (e.g. wherein the TYK2kinase contains no detectable markers of aberrant expression).

2.40 A method for treating, or alleviating or reducing the incidence of,a cancer in a subject (e.g. a mammalian subject such as a human),wherein the cancer is characterised by normal expression of TYK2 kinase(e.g. wherein the TYK2 kinase contains no detectable markers of aberrantexpression), which method comprises administering to the subject atherapeutically effective amount of a compound of formula (1) or formula(2), or a pharmaceutically acceptable salt thereof, as defined in anyone of Embodiments 1.1 to 1.93.

Examples of cancers (and their benign counterparts) which may be treated(or inhibited) include, but are not limited to tumours of epithelialorigin (adenomas and carcinomas of various types includingadenocarcinomas, squamous carcinomas, transitional cell carcinomas andother carcinomas) such as carcinomas of the bladder and urinary tract,breast, gastrointestinal tract (including the esophagus, stomach(gastric), small intestine, colon, bowel, colorectal, rectum and anus),liver (hepatocellular carcinoma), gall bladder and biliary system,exocrine pancreas, kidney (for example renal cell carcinoma), lung (forexample adenocarcinomas, small cell lung carcinomas, non-small cell lungcarcinomas, bronchioalveolar carcinomas and mesotheliomas), head andneck (for example cancers of the tongue, buccal cavity, larynx, pharynx,nasopharynx, tonsil, salivary glands, nasal cavity and paranasalsinuses), ovary, fallopian tubes, peritoneum, vagina, vulva, penis,testes, cervix, myometrium, endometrium, thyroid (for example thyroidfollicular carcinoma), brain, adrenal, prostate, skin and adnexae (forexample melanoma, basal cell carcinoma, squamous cell carcinoma,keratoacanthoma, dysplastic naevus); haematological malignancies (i.e.leukemias, lymphomas) and premalignant haematological disorders anddisorders of borderline malignancy including haematological malignanciesand related conditions of lymphoid lineage (for example acutelymphocytic leukemia [ALL], chronic lymphocytic leukemia [CLL], B-celllymphomas such as diffuse large B-cell lymphoma [DLBCL], follicularlymphoma, Burkitt's lymphoma, mantle cell lymphoma, T-cell lymphomas andleukaemias, natural killer [NK] cell lymphomas, Hodgkin's lymphomas,non-Hodgkin's lymphomas, hairy cell leukaemia, monoclonal gammopathy ofuncertain significance, plasmacytoma, multiple myeloma, andpost-transplant lymphoproliferative disorders), and haematologicalmalignancies and related conditions of myeloid lineage (for exampleacute myelogenous leukemia [AML], chronic myelogenous leukemia [CML],chronic myelomonocytic leukemia [CMML], hypereosinophilic syndrome,myeloproliferative disorders such as polycythaemia vera, essentialthrombocythaemia and primary myelofibrosis, myeloproliferative syndrome,myelodysplastic syndrome, and promyelocytic leukemia); tumours ofmesenchymal origin, for example sarcomas of soft tissue, bone orcartilage such as osteosarcomas, fibrosarcomas, chondrosarcomas,rhabdomyosarcomas, leiomyosarcomas, liposarcomas, angiosarcomas,Kaposi's sarcoma, Ewing's sarcoma, synovial sarcomas, epithelioidsarcomas, gastrointestinal stromal tumours, benign and malignanthistiocytomas, and dermatofibrosarcoma protuberans; tumours of thecentral or peripheral nervous system (for example astrocytomas, neuroasand glioblastomas, meningiomas, ependymomas, pineal tumours andschwannomas); endocrine tumours (for example pituitary tumours, adrenaltumours, islet cell tumours, parathyroid tumours, carcinoid tumours andmedullary carcinoma of the thyroid); ocular and adnexal tumours (forexample retinoblastoma); germ cell and trophoblastic tumours (forexample teratomas, seminomas, dysgerminomas, hydatidiform moles andchoriocarcinomas); and paediatric and embryonal tumours (for examplemedulloblastoma, neuroblastoma, Wilms tumour, and primitiveneuroectodermal tumours); or syndromes, congenital or otherwise, whichleave the patient susceptible to malignancy (for example XerodermaPigmentosum).

It is envisaged that particular cancers that will be susceptible bytreatment in accordance with the invention are hematopoietic cancers.Accordingly, in further embodiments, the invention provides:

2.41 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment or prophylaxis of a cancer (e.g. a cancer as defined hereinand in particular a hematopoietic cancer) in a patient who has beentested and diagnosed as being susceptible to treatment with a TYK2inhibitor.

2.42 A method for the prophylaxis or treatment of a cancer (e.g. acancer as defined herein and in particular a hematopoietic cancer),which method comprises administering to a patient, who has been testedand diagnosed as being susceptible to treatment with a TYK2 inhibitor,optionally in combination with radiotherapy or another chemotherapeuticagent a compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93.

2.43 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment or propylaxis of a cancer (e.g. a canceras defined herein and in particular a hematopoietic cancer) which ischaracterised by any one or more of aberrant expression of TYK2, andabnormally elevated levels of any one or more of phosphorylated STAT1,phosphorylated STAT3 and phosphorylated STAT5 and/or BCL2.

2.44 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment or prophylaxis of a cancer (e.g. a cancer as defined hereinand in particular a hematopoietic cancer) which is characterised by anyone or more of aberrant expression of TYK2, and abnormally elevatedlevels of any one or more of phosphorylated STAT1, phosphorylated STAT3and phosphorylated STAT5 and/or BCL2.

2.45 A method for the treatment or prophylaxis of a cancer (e.g. acancer as defined herein and in particular a hematopoietic cancer) whichis characterised by any one or more of aberrant expression of TYK2, andabnormally elevated levels of any one or more of phosphorylated STAT1,phosphorylated STAT3 and phosphorylated STAT5 and/or BCL2, which methodcomprises administering to a patient, optionally in combination withradiotherapy or another chemotherapeutic agent a therapeuticallyeffective amount of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93.

2.46 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in alleviating or reducing the incidence of a cancer (e.g.a cancer as defined herein and in particular a hematopoietic cancer)which is characterised by any one or more of aberrant expression ofTYK2, and abnormally elevated levels of any one or more ofphosphorylated STAT1, phosphorylated STAT3 and phosphorylated STAT5and/or BCL2.

2.47 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament fortreating, or alleviating or reducing the incidence of, a cancer (e.g. acancer as defined herein and in particular a hematopoietic cancer) whichis characterised by any one or more of aberrant expression of TYK2, andabnormally elevated levels of any one or more of phosphorylated STAT1,phosphorylated STAT3 and phosphorylated STAT5 and/or BCL2.

2.48 A method of treating, or alleviating or reducing the incidence of,a cancer (e.g. a cancer as defined herein and in particular ahematopoietic cancer) which is characterised by any one or more ofaberrant expression of TYK2, and abnormally elevated levels ofphosphorylated STAT1, phosphorylated STAT3 and phosphorylated STAT5and/or BCL2 in a subject (e.g. a mammalian subject, such as a human, inneed thereof), which method comprises administering to the subject atherapeutically effective amount of compound of formula (1) or formula(2), or a pharmaceutically acceptable salt thereof, as defined in anyone of Embodiments 1.1 to 1.93.

One particular subset of cancers against which the compounds of formulae(1) and (2) and their pharmaceutically acceptable salts should proveparticularly active are cancers which are characterised by upregulationof BCL2 and/or elevated levels of phosphorylated STAT1, phosphorylatedSTAT3 and phosphorylated STAT5 and/or BCL2. Methods of detectingphosphorylated STAT1, STAT3 and STAT5 are well-known to those in the artand include western blotting and flow cytometry (see for example themethods used in Pratt et al., “IL-6 driven STAT signalling incirculating CD4+ lymphocytes is a marker for early anticitrullinatedpeptide antibody-negative rheumatoid arthritis”, Ann Rheum Dis 2014;0:1-8). Examples of assays for the detection of STAT1, STAT3 and STAT5are described below in the experimental section of this application.Methods of detecting BCL2 are well-known to those in the art and includeflow cytometry and western blotting (see for example the methods used inCoustan-Smith et al., “Clinical Relevance of BCL-2 Overexpression inChildhood Acute Lymphoblastic Leukemia”, (1996), Blood., 87(3), pp1140-1146.)

In particular, it has been shown that the compounds of formulae (1) and(2) and their pharmaceutically acceptable salts may be useful in thetreatment of a hematopoietic cancer. The hematopoietic cancer may be aleukaemia, such as an Acute Lymphoblastic Leukaemia (for example, T-cellAcute Lymphoblastic Leukemia).

In some cancers (see for example the cell line in FIG. 2 appendedhereto), STAT3 is constitutively phosphorylated. Accordingly, theinvention also provides:

2.49 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment, or alleviating or reducing the incidenceof, a cancer which is characterised by constitutive phosphorylation ofSTAT3.

2.50 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment, or alleviating or reducing the incidence of, a cancer whichis characterised by constitutive phosphorylation of STAT3.

2.51 A method for the treatment, or alleviating or reducing theincidence of, a cancer in a subject (e.g. a mammalian subject such as ahuman), wherein the cancer is characterised by constitutivephosphorylation of STAT3, which method comprises administering to thesubject an effective therapeutic amount of a compound of formula (1) orformula (2), or a pharmaceutically acceptable salt thereof, as definedin any one of Embodiments 1.1 to 1.93.

A widespread problem encountered with anti-cancer drugs is thedevelopment of drug-resistant strains of particular cancers (see Bordenet al., Frontiers in Pharmacology, (2013) Vol. 4, Article 28, pages 1-8.Primary and acquired resistance can be caused by alterations to drugmetabolism or modifications of the drug target. Resistance due tochanges in drug metabolism can arise through modification of uptake,efflux and detoxification methods. Uptake could be affected by mutationsthat modify activity or reduce expression of surface receptors ortransporters. Enhanced drug efflux can be induced by increasedexpression of ATP binding cassette (ABC) membrane transporters such asP-gp. Cancer cells can develop resistance to drugs requiring metabolicactivation through decreased drug activation or enhanced binding ofdrugs by naturally occurring proteins.

Many cancer cells develop an over-reliance or dependency on an oncogene,Targeting such oncogenes forms the basis of targeted therapies. Forexample, gefitinib targets the epidermal growth factor receptor (EGFR)in non-small cell lung cancers. The long term effectiveness of suchtargeted drugs can be hindered due to the development of mutations inthe kinase domain, either increasing the catalytic efficiency of thekinase, or reducing the binding interaction of the targeted therapy.Cancer cells can also circumvent the effects of targeted inhibitors byamplifying alternative oncogenes or activating alternative survivalpathways.

In some drug-resistant cancers, a contributor to development ofresistance is the ability of the cancer cell to bypass the biochemicalpathways that are targeted by the drug. For example, acquired resistanceto phosphatidylinositol 3-kinase (PI3K) inhibitors such as ZSTK474 wasshown to be due to upregulation of insulin-like growth factor 1 receptorpathway, and that inhibition of this pathway with selective IGFR1inhibitors could overcome the acquired PI3K inhibitor resistance.Resistance can also arise from evasion of apoptotic pathways triggeredby the acquisition of either inactivating mutations in genes coding forapoptotic proteins such as p53 or activating mutations in genes encodingfor anti-apoptotic proteins such as BCL2.

Another mechanism of cancer cell drug resistance arises from fibroblastgrowth factor (FGF)-2 signalling. FGF-2 can provide cancer cells withpro-survival and mitogenic signals, conferring broad-spectrum resistanceto chemotherapeutic drugs. FGF-2 signalling induces the assembly of amulti-protein complex including protein kinase C (PKC)_(ε), v-raf murinesarcoma viral oncogene homolog 1 (B-RAF) and p70 S6 kinase β (S6K2),that enhances the selective translation of anti-apoptotic proteins suchas BCL-2 and inhibitors of apoptosis protein (IAP) family members whichare able to protect multiple cancer cell types from chemotherapy-inducedcell death. It has been shown that TYK2 is phosphorylated downstream ofFGF-2 signalling and is required for the full phosphorylation ofextracellular signal-regulated kinase (ERK) 1/2. Moreover TYK2 isnecessary for the induction of key anti-apoptotic proteins such as BCL-2and myeloid cell leukemia sequence (MCL) 1 to promote cell survivalfollowing FGF-2 signalling. Thus, it is envisaged that TYK2 inhibitorscould enhance the effectiveness of other cancer therapies modulated byFGF-2 driven cell survival.

It is envisaged that the compounds of the present invention will beuseful in treating cancers where resistance towards initial drugtreatment has arisen. Thus, the compounds can be used to target adifferent biochemical pathway (for example TYK2-STAT1-BCL2) than thebiochemical pathway targeted by the drug against which resistance hasdeveloped.

Accordingly, in a further embodiment (Embodiment 2.52), there isprovided a compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment of a subject suffering from a cancerwherein the subject has been receiving drug therapy for the cancer andwherein a reduction in effectiveness indicative of drug resistance hasbeen observed.

In another embodiment (Embodiment 2.53), there is provided a compound offormula (1) or formula (2), or a pharmaceutically acceptable saltthereof, as defined in any one of Embodiments 1.1 to 1.93 for use in thetreatment of a subject suffering from a cancer wherein the subject hasbeen receiving drug therapy for the cancer and wherein tests carried outon the subject and/or the cancer have established that the cancer isless sensitive to the drug than it was when treatment with the drug wasfirst initiated.

In further embodiments, (Embodiments 2.54 to 2.63), the inventionprovides:

2.54 A method for the treatment of a subject suffering from a cancerwherein the subject has been receiving drug therapy for the cancer andwherein a reduction in effectiveness indicative of drug resistance hasbeen observed, which method comprises administering to the subject aneffective therapeutic amount of a compound of formula (1) or formula(2), or a pharmaceutically acceptable salt thereof, as defined in anyone Embodiments 1.1 to 1.93.

2.55 A method for the treatment of a subject suffering from a cancerwherein the subject has been receiving drug therapy for the cancer andwherein tests carried out on the subject and/or the cancer haveestablished that the cancer is less sensitive to the drug than it waswhen treatment with the drug was first initiated, which method comprisesadministering to the subject an effective therapeutic amount of acompound of formula (1) or formula (2), or a pharmaceutically acceptablesalt thereof, as defined in any one Embodiments 1.1 to 1.93.

2.56 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any oneEmbodiments 1.1 to 1.93 in the manufacture of a medicament for thetreatment of a cancer in a subject wherein the subject has beenreceiving drug therapy for the cancer and wherein tests carried out onthe subject and/or the cancer have established that the cancer is lesssensitive to the drug than it was when treatment with the drug was firstinitiated.

2.57 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 in the manufacture of a medicament for thetreatment of a cancer in a subject wherein the subject has beenreceiving drug therapy for the cancer and wherein a reduction ineffectiveness indicative of drug resistance has been observed.

2.58 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment, or alleviating or reducing the incidenceof, a cancer of a type that has been shown to be resistant to one ormore other chemotherapeutic agents.

2.59 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment, or alleviating or reducing the incidence of, a cancer of atype that has been shown to be resistant to one or more otherchemotherapeutic agents.

2.60 A method for the treatment, or alleviating or reducing theincidence of, a cancer in a subject (e.g. a mammalian subject such as ahuman), wherein the cancer is of a type that has been shown to beresistant to one or more other chemotherapeutic agents, which methodcomprises administering to the subject an effective therapeutic amountof a compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93.

2.61 A compound of formula (1) or formula (2), or a pharmaceuticallyacceptable salt thereof, as defined in any one of Embodiments 1.1 to1.93 for use in the treatment, or alleviating or reducing the incidenceof, a cancer which is characterised by elevated levels of fibroblastgrowth factor (FGF)-2.

2.62 The use of a compound of formula (1) or formula (2), or apharmaceutically acceptable salt thereof, as defined in any one ofEmbodiments 1.1 to 1.93 for the manufacture of a medicament for thetreatment, or alleviating or reducing the incidence of, a cancer whichis characterised by elevated levels of fibroblast growth factor (FGF)-2.

2.63 A method of treating, or alleviating or reducing the incidence of,a cancer in a subject (e.g. a mammalian subject such as a human),wherein the cancer is characterised by elevated levels of fibroblastgrowth factor (FGF)-2, which method comprises administering to thepatient, a therapeutically effective amount of a compound of formula (1)or formula (2), or a pharmaceutically acceptable salt thereof, asdefined in any one of Embodiments 1.1 to 1.93.

In the foregoing embodiments, the drug to which the cancer has developedresistance is typically one which does not make use of inhibition ofTYK2 kinase as its primary anti-cancer effect. More particularly, thedrug is one which has an IC₅₀ of greater than 20 μM against TYK2 kinasein a kinase inhibition assay, and more usually greater than 50 μM (forexample in the range 50-500 μM. In one embodiment, the drug to which thecancer has developed resistance is substantially inactive against TYK2kinase.

The compounds of the invention can also be used for the treatment of acancer in a patient who has not previously received chemotherapy for thetreatment of that cancer, and wherein the cancer is known to beresistant to one or more anti-cancer drugs.

In each of the foregoing embodiments 2.52 to 2.63, the drug-resistantcancer can be selected from categories A to H below and any one or moreindividual combinations of drugs and cancers disclosed therein:

A. Cells that have shown intrinsic or acquired resistance to DNA-bindingagents such as:

Cis-platin, Oxaliplatin, Carboplatin, Cyclophosphamide, Melphalan,Temazolomide, Carmustine, Ifosfamide, Streptozotocin, Epirubicin,Doxorubicin, Dactinomycin;

in cancers such as:

brain, testicular, head and neck cancers, Hodgkin's disease, pancreatic,ovarian, bladder, breast and lung cancers, acute leukaemias,endometrial, thyroid, Wilm's tumour, Ewing's sarcoma, rhabdomyelosarcomaand neuroblastoma (NB resistance to cis-platin has been shown to beovercome in non-small cell lung cancer using the JAK/STAT inhibitorruxolitinib);

B. Cells that have shown intrinsic or acquired resistance toTopoisomerase I and II inhibitors such as:

Etoposide, Topotecan, Irinotecan;

in cancers such as:

Lung cancer, Kaposi's sarcoma, breast, ovarian, colon and rectal cancer;

C. Cells that have shown intrinsic or acquired resistance toAnti-metabolites such as: Methotrexate, 5-Fluorouracil, Cytarabine,Gemcitabine, Capecitabine, 6-Mercaptopurine, 6-Thioguanine;

in cancers such as:

Acute lymphoblastic leukaemia, choriocarcinoma, breast, head and neck,lung, cervical, basal cell skin, gastrointestinal, colon, stomach,rectum, pancreas, prostate and bladder cancers, acute and chronicmyelogenous leukaemia, acute lymphocytic leukaemia and acutemyelomonocytic leukaemia;

D. Cells that have shown intrinsic or acquired resistance to mitoticspindle inhibitors such as:

Vincristine, Vinblastine, Paclitaxel, Docetaxel

in cancers such as:

acute lymphocytic leukaemia, Wilm's tumour, rhabdomeyelosarcoma, breast,cervical, ovarian and testicular cancers, Hodgkin's disease, Kaposi'ssarcoma, and lung, bladder, head and neck cancers.

E. Cells that have shown intrinsic or acquired resistance to kinaseinhibitors such as: Dasatinib, Erlotinib, Gefitinib, Imatinib,Lapatinib, Nilotinib, Sorafenib, Sunitinib, Afatinib, Axitinib,Bosutinib, Crizotinib, Cobimetinib, Cabozantinib, Ibrutinib, Pazopanib,Ruxolitinib, Vemurafenib, Temsirolimus, Everolimus

in cancers such as:

lung and renal cancers, chronic myelogenous leukaemia, melanoma, thyroidcancer, neuroblastoma, gastrointestinal stromal tumours, breast cancer,myelofibrosis, lymphoma, and neuroendocrine tumours of the pancreas.

F. Cells that have shown intrinsic or acquired resistance to Aromataseinhibitors such as:

Anastrozole, Letrozole, Exemestane

in cancers such as:

breast cancer.

G. Cells that have shown intrinsic or acquired resistance to proteasomeinhibitors such as:

Bortezomib

in cancers such as multiple myeloma; and

H. Cells that have shown intrinsic or acquired resistance to othersmall-molecule or monoclonal antibody cancer therapies such as:

Vorinostat, Abiraterone, Venetoclax, Trastuzumab, Bevacizumab,Rituximab, Ipilimumab, Pembrolizumab, nivolumab.

in cancers such as:

T-cell lymphoma, prostate cancer, chronic lymphocytic leukaemia,melanoma and Hodgkin's lymphoma.

Methods for the Preparation of Compounds of Formula (1)

The compounds of formulae (1) and (2) and their pharmaceuticallyacceptable salts can be prepared by the methods described inInternational patent application WO2008/139161 (Sareum) andInternational patent application WO 2015/032423 (Sareum).

Pharmaceutical Formulations

While it is possible for the active compound to be administered alone,it is preferable to present it as a pharmaceutical composition (e.g.formulation) comprising at least one active compound of the inventiontogether with one or more pharmaceutically acceptable excipients such ascarriers, adjuvants, diluents, fillers, buffers, stabilisers,preservatives, lubricants, or other materials well known to thoseskilled in the art, and optionally other therapeutic or prophylacticagents.

The term “pharmaceutically acceptable” as used herein refers tocompounds, materials, compositions, and/or dosage forms which are,within the scope of sound medical judgment, suitable for use in contactwith the tissues of a subject (e.g. human) without excessive toxicity,irritation, allergic response, or other problems or complication,commensurate with a reasonable benefit/risk ratio. Each excipient mustalso be “acceptable” in the sense of being compatible with the otheringredients of the formulation.

The pharmaceutical compositions can be in any form suitable for oral,parenteral, topical, intranasal, ophthalmic, otic, rectal,intra-vaginal, or transdermal administration. Where the compositions areintended for parenteral administration, they can be formulated forintravenous, intramuscular, intraperitoneal, subcutaneous administrationor for direct delivery into a target organ or tissue by injection,infusion or other means of delivery.

Pharmaceutical dosage forms suitable for oral administration includetablets, capsules, caplets, pills, lozenges, syrups, solutions, powders,granules, elixirs and suspensions, sublingual tablets, wafers or patchesand buccal patches.

Pharmaceutical compositions containing compounds of the formulae (1) and(2), or their pharmaceutically acceptable salts, can be formulated inaccordance with known techniques, see for example, Remington'sPharmaceutical Sciences, Mack Publishing Company, Easton, Pa., USA.

Thus, tablet compositions can contain a unit dosage of active compoundtogether with an inert diluent or carrier such as a sugar or sugaralcohol, eg; lactose, sucrose, sorbitol or mannitol; and/or a non-sugarderived diluent such as sodium carbonate, calcium phosphate, calciumcarbonate, or a cellulose or derivative thereof such as methylcellulose, ethyl cellulose, hydroxypropyl methyl cellulose, and starchessuch as corn starch. Tablets may also contain such standard ingredientsas binding and granulating agents such as polyvinylpyrrolidone,disintegrants (e.g. swellable crosslinked polymers such as crosslinkedcarboxymethylcellulose), lubricating agents (e.g. stearates),preservatives (e.g. parabens), antioxidants (e.g. BHT), buffering agents(for example phosphate or citrate buffers), and effervescent agents suchas citrate/bicarbonate mixtures. Such excipients are well known and donot need to be discussed in detail here.

Capsule formulations may be of the hard gelatin or soft gelatin varietyand can contain the active component in solid, semi-solid, or liquidform. Gelatin capsules can be formed from animal gelatin or synthetic orplant derived equivalents thereof.

The solid dosage forms (e.g. tablets, capsules etc.) can be coated orun-coated, but typically have a coating, for example a protective filmcoating (e.g. a wax or varnish) or a release controlling coating. Thecoating (e.g. a Eudragit™ type polymer) can be designed to release theactive component at a desired location within the gastro-intestinaltract. Thus, the coating can be selected so as to degrade under certainpH conditions within the gastrointestinal tract, thereby selectivelyreleasing the compound in the stomach or in the ileum or duodenum.

Instead of, or in addition to, a coating, the drug can be presented in asolid matrix comprising a release controlling agent, for example arelease delaying agent which may be adapted to selectively release thecompound under conditions of varying acidity or alkalinity in thegastrointestinal tract. Alternatively, the matrix material or releaseretarding coating can take the form of an erodible polymer (e.g. amaleic anhydride polymer) which is substantially continuously eroded asthe dosage form passes through the gastrointestinal tract. As a furtheralternative, the active compound can be formulated in a delivery systemthat provides osmotic control of the release of the compound. Osmoticrelease and other delayed release or sustained release formulations maybe prepared in accordance with methods well known to those skilled inthe art.

Compositions for topical use include ointments, creams, sprays, patches,gels, liquid drops and inserts (for example intraocular inserts). Suchcompositions can be formulated in accordance with known methods.

Compositions for parenteral administration are typically presented assterile aqueous or oily solutions or fine suspensions, or may beprovided in finely divided sterile powder form for making upextemporaneously with sterile water for injection.

Compositions for parenteral administration may be formulated foradministration as discrete dosage units or may be formulated foradministration by infusion.

Examples of formulations for rectal or intra-vaginal administrationinclude pessaries and suppositories which may be, for example, formedfrom a shaped mouldable or waxy material containing the active compound.

Compositions for administration by inhalation may take the form ofinhalable powder compositions or liquid or powder sprays, and can beadministrated in standard form using powder inhaler devices or aerosoldispensing devices. Such devices are well known. For administration byinhalation, the powdered formulations typically comprise the activecompound together with an inert solid powdered diluent such as lactose.

The compounds of the inventions will generally be presented in unitdosage form and, as such, will typically contain sufficient compound toprovide a desired level of biological activity. For example, aformulation intended for oral administration may contain from 0.1milligrams to 2 grams of active ingredient, more usually from 10milligrams to 1 gram, for example, 50 milligrams to 500 milligrams.

The active compound will be administered to a patient in need thereof(for example a human or animal patient) in an amount sufficient toachieve the desired therapeutic effect.

Methods of Treatment

It is envisaged that the compounds of the formulae (1) and (2) and theirpharmaceutically acceptable salts as defined in any one of Embodiments1.1 to 1.93 will be useful in the prophylaxis or treatment ofproliferative diseases, such as cancer, and in particular in theprophylaxis or treatment of hematopoietic cancers, particularly T-ALL.Examples of such cancers are set out above.

The compounds will typically be administered in amounts that aretherapeutically or prophylactically useful and which generally arenon-toxic. However, in certain situations (for example in the case oflife threatening diseases), the benefits of administering a compound ofthe formulae (1) or (2), or a pharmaceutically acceptable salt thereof,may outweigh the disadvantages of any toxic effects or side effects, inwhich case it may be considered desirable to administer compounds inamounts that are associated with a degree of toxicity.

The compounds may be administered over a prolonged term to maintainbeneficial therapeutic effects or may be administered for a short periodonly. Alternatively, they may be administered in a pulsatile orcontinuous manner.

The compound of formula (1) or (2), or a pharmaceutically acceptablesalt thereof, will generally be administered to a subject in need ofsuch administration, for example a human patient.

A typical daily dose of the compound can be up to 1000 mg per day, forexample in the range from 0.01 milligrams to 10 milligrams per kilogramof body weight, more usually from 0.025 milligrams to 5 milligrams perkilogram of body weight, for example up to 3 milligrams per kilogram ofbodyweight, and more typically 0.15 milligrams to 5 milligrams perkilogram of bodyweight although higher or lower doses may beadministered where required.

By way of example, an initial starting dose of 12.5 mg may beadministered 2 to 3 times a day. The dosage can be increased by 12.5 mga day every 3 to 5 days until the maximal tolerated and effective doseis reached for the individual as determined by the physician.Ultimately, the quantity of compound administered will be commensuratewith the nature of the disease or physiological condition being treatedand the therapeutic benefits and the presence or absence of side effectsproduced by a given dosage regimen, and will be at the discretion of thephysician.

The compounds of the formulae (1) and (2) or their pharmaceuticallyacceptable salts can be administered as the sole therapeutic agent orthey can be administered in combination therapy with one or more othercompounds such as steroids or interferons.

Combination Therapy

It is envisaged that the compounds of Embodiments 1.1 to 1.93 will beuseful either as sole chemotherapeutic agents or, more usually, incombination therapy with chemotherapeutic agents or radiation therapy inthe prophylaxis or treatment of a range of proliferative disease statesor conditions. Examples of such disease states and conditions are setout above.

Particular examples of chemotherapeutic agents that may beco-administered with the compounds of Embodiments 1.1 to 1.93 include:

-   -   Topoisomerase I inhibitors    -   Antimetabolites: (e.g. Cytarabine)    -   Tubulin targeting agents    -   DNA binder and topoisomerase II inhibitors    -   EGFR inhibitors (e.g. Gefitinib—see Biochemical Pharmacology 78        2009 460-468)    -   mTOR inhibitors (e.g. Everolimus)    -   PI3K pathway inhibitors (e.g. PI3K, PDK1)    -   Akt inhibitors    -   Alkylating Agents (e.g. temozolomide)    -   Monoclonal Antibodies.    -   Anti-Hormones    -   Signal Transduction inhibitors    -   Proteasome Inhibitors    -   DNA methyl transferase inhibitors    -   Cytokines and retinoids    -   Hypoxia triggered DNA damaging agents (e.g. Tirapazamine)    -   Aromatase inhibitors    -   Anti Her2 antibodies, (see for example        http://www.wipo.int/pctdb/en/wo.jsp?wo=2007056118)    -   Anti cd20 antibodies    -   Inhibitors of angiogenesis    -   HDAC inhibitors    -   MEK inhibitors    -   B-Raf inhibitors    -   ERK inhibitors    -   HER2 small molecule inhibitors e.g. lapatinib    -   Bcr-Abl tyrosine-kinase inhibitors e.g. imatinib    -   CDK4/6 inhibitor e.g. Ibrance    -   Mps1/TTK inhibitors    -   Aurora B inhibitors    -   FLT3 kinase inhibitors    -   IDH1 or IDH2 inhibitors    -   BRD4 inhibitors    -   Inhibitors of immune checkpoint blockade signalling components        including PD1, PDL-1 and CTLA4; and    -   steroidal compounds.

In one embodiment, the compounds of Embodiments 1.1 to 1.93 may beadministered in combination with an alkylating agent. Examples ofalkylating agents include nitrogen mustards (e.g. cyclophosphamide,chlormethine and uramustine), nitrosoureas, alkyl sulfonates andplatinum-based chemotherapeutics. In a particular embodiment, thealkylating agent is cyclophosphamide.

Methods of Diagnosis

Prior to administration of a compound of the formula (1) or (2), or apharmaceutically acceptable salt thereof, a patient may be screened todetermine whether a disease or condition, and in particular a cancer,from which the patient is or may be suffering is one which would besusceptible to treatment with a compound having activity against TYK2.

A subject (e.g. patient) may be subjected to a diagnostic test to detecta marker indicative of the presence of a cancer in which TYK2 isimplicated, or a marker indicative of susceptibility to the said cancer.For example, subjects may be screened for genetic markers indicative ofthe activation of the TYK2-STAT1 pathway, such as BCL2. This activationmay occur as a result of a genetic mutation in the TYK2 gene oractivation of interleukin (IL)-10 signalling.

The genetic marker can comprise a particular allele or single nucleotidepolymorphism of the TYK2 gene which is indicative of susceptibility tocancers, such as T-ALL cancers (see for example Sanda et al., CancerDiscov., (2013), 3(5), pp 564-577.) The genetic marker can, for example,be a single nucleotide polymorphism in the TYK2 gene, or it can be ahaplotype comprising a single nucleotide polymorphism in the TYK2 geneand a polymorphism in another gene.

The diagnostic tests are typically conducted on a biological sampleselected from blood samples, biopsy samples, stool biopsies, sputum,chromosome analysis, pleural fluid, peritoneal fluid, or urine.

Methods of identifying genetic markers such as single nucleotidepolymorphisms are well known. Examples of suitable methods foridentifying such markers are described in Tomasson et al., “Somaticmutations and germline sequence variants in the expressed tyrosinekinase genes of patients with de novo acute myeloid leukemia”, Blood, 1May 2008, 111, 9, 4797.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1E show Western Blot analyses of cell lysates obtained byincubating Jurkat cells with Compounds 19, 20, 25 and 29 and threebenchmark inhibitors (GLPG0634 (Filgotinib, developed by Galapagos),TG101209 and GDC-046) as comparative examples and then probing withantibodies against phospho-TYK2/total-TYK2, phospho-STAT1/total-STAT1,phospho-STAT3/total-STAT3, phospho-STAT5/total-STAT5 and Actin.

FIG. 2 shows a Western blot analysis of cell lysates obtained byincubating MOLT-4 cells with Compounds 25 and 29 and three benchmarkinhibitors (GLPG0634 (Filgotinib, developed by Galapagos), TG101209 andGDC-046) as comparative examples and then probing with antibodiesagainst PARP and Actin.

FIG. 3 shows a Western blot analysis of cell lysates obtained byincubating CCRF-HSB-2 cells with Compounds 25 and 29 and then probingwith antibodies against phospho-TYK2 & total-TYK2, phospho-STATs 1/3/5 &total-STATs 1/3/5, BCL2 and PARP.

FIG. 4 is a plot of plasma concentrations of Compound 25 against timeafter dose in male SCID mice implanted with MOLT-4 tumour cells.

FIG. 5 is a plot of tumour concentrations of Compound 25 against timeafter dose in male SCID mice implanted with MOLT-4 tumour cells.

FIG. 6 shows a Western blot analysis for levels of phosphorylated STAT1and phosphorylated TYK2 in homogenised extracts from the tumour tissuesof male SCID mice implanted with MOLT-4 tumour cells and subsequentlytreated with Compound 25 after tumour development.

FIG. 7 is a plot of tumour volume against treatment time for male SCIDmice bearing MOLT-4 tumours and treated with Compound 25 orcyclophosphamide.

FIG. 8 is a plot of tumour volume against treatment time for male SCIDmice bearing CCRF-HSB-2 tumours and treated with Compound 29 orcyclophosphamide.

FIG. 9 is a plot of tumour weight for male SCID mice bearing CCRF-HSB-2tumours treated with Compound 29 or cyclophosphamide.

FIG. 10 is a plot of tumour volume against treatment time for male SCIDmice bearing MOLT-4 tumours and treated with Compound 29,cyclophosphamide or a combination thereof.

FIG. 11 is a plot of tumour weight for male SCID mice bearing MOLT-4tumours treated with Compound 29, cyclophosphamide or a combinationthereof.

EXAMPLES

The invention will now be illustrated, but not limited, by reference tothe specific embodiments described in the following examples.

Example 1

Enzyme Inhibition

Compounds of the invention were assayed for their ability to inhibitTYK2 kinase and other JAK kinases.

Substrates and kinases used in the assays are identified in Table 2below.

Kinase assays were performed at Reaction Biology Corp., Malvern, Pa.,USA, using the following general procedure:

-   1) Prepare indicated substrate in freshly prepared Base Reaction    Buffer (20 mM Hepes pH 7.5, 10 mM MgCl₂, 1 mM EGTA, 0.02% Brij35,    0.02 mg/ml BSA, 0.1 mM Na₃VO₄, 2 mM DTT, 1% DMSO).-   2) Deliver cofactors (1.5 mM CaCl₂, 16 ug/mL Calmodulin, 2 mM MnCl₂)    to the substrate solution above-   3) Deliver indicated kinase into the substrate solution and gently    mix-   4) Deliver varying concentrations of test compound in DMSO into the    kinase reaction mixture-   5) Deliver ³³P-ATP (specific activity 0.01 μCi/μL final) into the    reaction mixture to initiate the reaction-   6) Incubate kinase reaction for 120 min at room temperature-   7) Reactions are spotted onto P81 ion exchange filter paper (Whatman    #3698-915)-   8) Unbound phosphate is removed by washing filters extensively in    0.75% Phosphoric acid.-   9) ³³P signal was determined using Typhoon phosphorimagers (GE    Healthcare). After subtraction of background derived from control    reactions containing inactive enzyme, IC₅₀ values were determined    using the nonlinear regression function in Prism (Graphpad    software).

TABLE 2 Protein Protein HUGO Genbank Accession Name symbol SubstrateAccession # # Clone Expression Tag JAK1 JAK1 pEY NP_002218.2 P23458 aaBaculovirus N- 866-1154 in Sf21 terminal insect cells GST tag JAK2 JAK2pEY NP_004963 O60674 aa Baculovirus N- 809-1132 in Sf21 terminal +ginsect cells GST tag JAK3 JAK3 JAK3tide NP_000206 P52333 aa BaculovirusN- 781-1124 in Sf21 terminal insect cells GST tag TYK2 TYK2 AXLtideNP_003322.2 P29597 Aa Baculovirus N- 833-1187 in Sf21 terminal insectcells GST tag

Substrates:

AXLtide=[KKSRGDYMTMQIG]

JAK3tide=[Ac-GEEEEYFELVKKKK-NH₂]

pEY=poly Glu-Tyr [Glu:Tyr (4:1), M.W.=5,000-20,000]

The results are shown in Table 3 below.

TABLE 3 Compound Number (and method of In Vitro Enzyme IC₅₀ (nM)preparation) STRUCTURE TYK2 JAK1 JAK2 JAK3 Compound 1 (Example Q-3 inWO2008/139161)

13.5 90.2 234.7 404.8 Compound 2 (Example Q-25 in WO2008/139161)

14.6 78.2 146.6 418.8 Compound 3 (Example Q-26 in WO2008/139161)

5.3 47.6 95.0 359.0 Compound 4 (Example Q-27 in WO2008/139161)

13.8 65.6 109.0 387.2 Compound 5 (Example Q-20 in WO2008/139161)

9.2 88.6 112.1 218.9 Compound 6 (Example Q-51 in WO2008/139161)

25.0 192.4 297.1 471.6 Compound 7 (Example Q-54 in WO2008/139161)

9.8 201.5 261.0 419.3 Compound 8 (Example Q-53 in WO2008/139161)

12.9 201.0 267.5 408.5 Compound 9 (Example U-2 in WO2008/139161)

22.7 75.6 267.4 423.4 Compound 10 (Example U-3 in WO2008/139161)

20.5 183.3 311.4 397.2 Compound 11 (Example U-4 in WO2008/139161)

15.1 189.6 338.4 387.7 Compound 12 (Example U-6 in WO2008/139161)

23.41 168.6 292.4 346.2 Compound 13 (Example U-7 in WO2008/139161)

11.2 123.0 181.6 341.5 Compound 14 (Example U-12 in WO2008/139161)

9.6 67.22 36.0 125.9 Compound 15 (Example U-16 in WO2008/139161)

7.5 41.1 101.3 194.9 Compound 16 (Example U-17 in WO2008/139161)

8.4 58.1 118.8 199.1 Compound 17 (Example U-21 in WO2008/139161)

13.7 152.8 167.2 99.2 Compound 18 (Example U-18 in WO2008/139161)

13.8 118.3 191.8 164.6 Compound 19 Example 19 in WO2015/032423

2.3 21.9 87.7 214 Compound 20 Example 20 in WO2015/032423

2.7 28.7 72.6 165 Compound 21 Example 21 in WO2015/032423

68.3 241 412 2180 Compound 22 Example 22 in WO2015/032423

183 843 663 5500 Compound 23 Example 23 in WO2015/032423

1.89 63.3 61.9 240 Compound 24 Example 24 in WO2015/032423

5.11 157 125 167 Compound 25 Example 25 in WO2015/032423

0.564 28.9 30.9 43.2 Compound 26 Example 26 in WO2015/032423

2.98 100 87.8 132 Compound 27 Example 27 in WO2015/032423

1.21 72.2 93.3 233 Compound 28 Example 28 in WO2015/032423

1.77 108 122 194 Compound 29 Example 29 in WO2015/032423

0.617 16.8 40.3 90.8 Compound 30 Example 30 in WO2015/032423

1.52 83.4 106 164 Compound 31 Example 31 in WO2015/032423

4.41 222 213 390 Compound 32 Example 32 in WO2015/032423

31 1970 1590 5370 Compound 33 Example 33 in WO2015/032423

5.47 135 153 516

Example 2

Cell Proliferation Assay

Compounds 19, 20, 25 and 29 were investigated in a panel of five celllines:

-   -   Jurkat    -   MOLT-4    -   CCRF-CEM    -   Loucy    -   CCRF-HSB-2

Jurkat, MOLT-4, CCRF-CEM and CCRF-HSB-2 cells are all TYK2-dependentT-ALL cells.

Loucy cells are TYK2-independent T-ALL cell lines.

Dexamethasone, Etoposide and Paclitaxel were used as positive controls.

Compound effects were studied 7 days after compound addition

Protocol

-   -   Cells were seeded in 384-well plates at the appropriate density        and allowed to adhere overnight prior to addition of compound or        vehicle control.    -   Compounds 19, 20, 25 and 29 were prepared from DMSO stocks to        give a final concentration range of between approximately 3 nM        and 30 μM. The final DMSO concentration was constant at 0.15%.    -   Test compounds were incubated with the cells for 7 days at        37° C. 5% CO₂ in a humidified atmosphere.    -   A volume of ATPlite reagent, equal to the volume of cell culture        medium present in each well, was then added and plates were        shaken at room temperature (RT) for 2 min, and incubated at RT        for a further 10 min. Luminescent product was detected using a        BMG FLUOstar plate reader.    -   The data were analysed using a 4-parameter logistic equation in        GraphPad Prism.

The results are shown in Table 5 below.

TABLE 5 Cell Proliferation IC₅₀ (μM) Compound CCRF- CCRF- Number JurkatMOLT-4 CEM Loucy HSB-2 Compound 19 8% 12 34% 20 17 inh. @ inh. @ 30 μM30 μM Compound 20 2.1 3.1 8.9 3.9 2.8 Compound 25 0.15 0.27 0.38 0.350.43 Compound 29 0.6 1.2 1.8 1.7 1.4 Etoposide 94 7.7 17 33 4.7Dexamethasone 5% 21% 59 25% 49 inh. @ inh. @ inh. @ 10 μM 10 μM 10 μMPaclitaxel 1.8 0.66 4.4 2.2 1.3

Example 3

Western Blot Assay—Short Term Compound Treatment

Jurkat cells were treated with Compounds 19, 20, 25 and 29 (ofExample 1) and three benchmark inhibitors (GLPG0634 (Filgotinib,developed by Galapagos), TG101209 and GDC-046) as comparative examplesusing the protocol set out below.

Cells were incubated with compounds at five concentrations (3, 1, 0.3,0.1 & 0.03 μM) for 1 hr, then stimulated with INFα for 20 m, beforecells were harvested.

Cell lysates were analysed by Western blot and then probed withantibodies against the following:

-   -   phospho-TYK2/total-TYK2    -   phospho-STAT1/total-STAT1    -   phospho-STAT3/total-STAT3    -   phospho-STAT5/total-STAT5    -   Actin

The details of the antibodies are set out in the table below.

Incubation/ Block Antigen Size (kDa) Supplier Cat. No. DilutionConditions Secondary TYK2 134 Cell 9312 1:500 o/n 4° C. Anti-RabbitSignalling 5% BSA pTYK2 134 Cell 9321 1:500 o/n 4° C. Anti-Rabbit(Tyr1054/1055) Signalling 5% BSA JAK1 130 Cell 3344 1:5000 o/n 4° C.Anti-Rabbit Signalling 5% BSA pJAK1 130 Cell 3331 1:500 o/n 4° C.Anti-Rabbit (Tyr1022/1023) Signalling 5% BSA JAK2 125 Cell 3230 1:1000o/n 4° C. Anti-Rabbit Signalling 5% BSA pJAK2 125 Cell 3776 1:1000 o/n4° C. Anti-Rabbit (Tyr1022/1023) Signalling 5% BSA STAT1 84/91 Cell 91751:500 o/n 4° C. Anti-Rabbit Signalling 5% BSA pSTAT1 84/91 Cell 76491:500 o/n 4° C. Anti-Rabbit (Tyr701) Signalling 5% BSA STAT3 79/86 Cell12640 1:3000 o/n 4° C. Anti-Rabbit Signalling 5% BSA pSTAT3 79/86 Cell9145 1:2000 o/n 4° C. Anti-Rabbit (Tyr705) Signalling 5% BSA STAT5 90Cell 9363 1:500 o/n 4° C. Anti-Rabbit Signalling 5% BSA pSTAT5 90 Cell4322 1:1000 o/n 4° C. Anti-Rabbit (Tyr694) Signalling 5% BSA Beta Actin45 Sigma A5441 1:200,000 o/n 4° C. Anti-Mouse 5% Milk

Protocol

-   -   Cell were plated in 6-well plates at 2.5×10⁶ cells per well in 2        ml of media (RPMI+10% FBS) and incubated for at least 1 h at 37°        C., 5% CO₂.    -   Cells were treated with the indicated concentrations of        compounds for 1 hrs.    -   Cells were then stimulated with IFNα (6000 U/ml) for 20 min at        37° C., 5% CO₂.    -   Cells were harvested by centrifuging at 12,000 rpm for 1 min (4°        C.), washed in ice cold PBS and centrifuged again at 12,000 rpm        for 1 min (4° C.).    -   The supernatant was removed and the cell pellet snap frozen on        dry ice.    -   Cells were lysed in RIPA buffer (with protease and phosphatase        inhibitors) and incubated on ice for 30 min.    -   Cellular debris was pelleted at 13,000 rpm for 5 min at 4° C.,        supernatant was transferred to a fresh tube.    -   Protein concentration was estimated using a BCA assay.    -   50 μg of protein was loaded onto 4-12% NuPAGE Novex Bis-Tris        protein gels (MOPs buffer).    -   Protein was transferred to a PVDF membrane using dry transfer        (iBlot) and western blotting performed against the antigens of        interest.

Results

The Western Blot analyses are shown in FIGS. 1A to 1E.

An increase in TYK2 activation loop phosphorylation (Tyr1054/1055) wasobserved following compound exposure (FIG. 1A), a phenomenon that hasbeen previously observed with other ATP-competitive JAK familyinhibitors (see for example Andraos, R. et al., “Modulation ofActivation-Loop Phosphorylation by JAK Inhibitors is Binding ModeDependent”, Cancer Discovery, June 2012, 513) suggesting that compoundsare interacting at the ATP-binding site of TYK2. A dose-dependentsuppression of STAT1, STAT3 and STAT5 phosphorylation was also observed(FIG. 1B-C), consistent with TYK2 inhibition.

Example 4

Western Blot Assay—Chronic Compound Treatment

MOLT-4 cells were treated with Compounds 25 and 29 (of Example 1) andthree benchmark inhibitors (GLPG0634 (Filgotinib, developed byGalapagos), TG101209 and GDC-046) as comparative examples at fiveconcentrations (3, 1, 0.3, 0.1 and 0.03 μM), for 48 hrs.

Cell lysates were analysed by Western blot and probed with antibodiesagainst PARP and Actin.

The details of the antibodies used are set out in the table below.

Incubation / Block Antigen Size (kDa) Supplier Cat. No. DilutionConditions Secondary PARP 116/89 Cell 9542 1:2,000 o/n 4° C. Anti-RabbitSignalling 5% Milk Beta Actin 45 Sigma A5441 1:200,000 o/n 4° C.Anti-Mouse 5% Milk

Protocol

-   -   Cell were plated in 6-well plates at 4e6 cells per well in 6 ml        of media (RPMI+10% FBS) and incubated for at least 1 h at 37°        C., 5% CO₂.    -   Cells were treated with the indicated concentrations of        compounds for 48 hrs.    -   Cells were harvested by centrifuging at 12,000 rpm for 1 min (4°        C.), washed in ice cold PBS and centrifuged again at 12,000 rpm        for 1 min (4° C.).    -   The supernatant was removed and the cell pellet snap frozen on        dry ice.    -   Cells were lysed in RIPA buffer (with protease and phosphatase        inhibitors) and incubated on ice for 30 min.    -   Cellular debris was pelleted at 13,000 rpm for 5 min at 4° C.,        supernatant was transferred to a fresh tube.    -   Protein concentration was estimated using a BCA assay.    -   30 μg of protein was loaded onto 4-12% NuPAGE Novex Bis-Tris        protein gels (MOPs buffer).    -   Protein was transferred to a PVDF membrane using dry transfer        (iBlot) and western blotting performed against the antigens of        interest.

Results

Western blot analysis is shown in FIG. 2.

The presence of cleaved PARP at concentrations ≥1 μM (Compound 25) and≥3 μM (Compound 29) shows that compounds cause apoptosis of MOLT-4 cellsat such concentrations, and that the anti-proliferative effects of thecompounds are therefore likely due to induction of apoptosis, ratherthan due to affecting progress through the cell-cycle.

Example 5

Western Blot in CCRF-HSB-2 Cell Line

CCRF-HSB-2 cells show constitutive phosphorylation of STAT1, STAT3 andSTAT5 in the absence of IFNα stimulation by Western blot. Cells weretreated with Compounds 25 and 29 for 48 h before being harvested.

Cell lysates were analysed by Western blot and probed with antibodiesagainst the following:

-   -   phospho-TYK2 & total-TYK2    -   phospho-STATs 1/3/5 & total-STATs 1/3/5    -   Bcl-2    -   PARP

Protocol

-   -   CCRF-HSB-2 cells were plated in 6-well plates at 5e6 cells per        well in 10 ml of media (IMDM+10% FBS) and incubated for at least        1 h at 37° C., 5% CO2.    -   Cells were treated with the indicated concentrations of        compounds for 48 hrs.    -   Cells were harvested by centrifuging at 12,000 rpm for 1 min (4°        C.), washed in ice cold PBS and centrifuged again at 12,000 rpm        for 1 min (4° C.).    -   The supernatant was removed and the cell pellet snap frozen on        dry ice.    -   Cells were lysed in RIPA buffer (with protease and phosphatase        inhibitors) and incubated on ice for 30 min.    -   Cellular debris was pelleted at 13,000 rpm for 5 min at 4° C.,        supernatant was transferred to a fresh tube.    -   Protein concentration was estimated using a BCA assay.    -   25 μg of protein was loaded onto 4-12% NuPAGE Novex Bis-Tris        protein gels (MOPs buffer).    -   Protein was transferred to a PVDF membrane using dry transfer        (iBlot) and western blotting performed against the antigens of        interest.

Results

Western blot analysis is shown in FIG. 3. The Western blots show doseresponsive reduction in the phosporylated signals, induction of cleavedParp and reduction in levels of the anti-apoptotic protein, BCL-2consistent with TYK2 inhibition having an anti-proliferative effect inT-ALL cell lines through apoptosis caused by reductions in BCL-2 levels

Example 6

PKPD Study in Male SCID Mice Bearing MOLT-4-Tumours

Male SCID mice were implanted with MOLT-4 tumour cells (1×10⁷ in 50%matrigel). When tumours reached approximately 150 mm³ animals received asingle dose of test compound. Animals to be sampled at 24 hrs alsoreceived a second dose at 12 hrs.

At 1, 6 and 24 h animals were sacrificed and plasma prepared. Tumourtissue was removed and divided into 2 sections—one for bioanalysis andthe second for homogenisation for western blotting.

Tumour tissue was homogenised in lysis buffer supplemented with proteaseand phosphatase inhibitors. Protein in individual samples was quantifiedusing a commercially available BCA kit.

50 μg total protein was run on a 4-20% pre-cast gel and transferred toPVDF membrane before being incubated with the following antibodies:

-   -   pSTAT1    -   STAT1    -   pTYK2    -   TYK2    -   Cleaved PARP    -   B-actin    -   Anti-rabbit IgG

Results

Pharmacokinetic analysis of plasma showed a maximal exposure of Compound25 one hour after dosing, with a maximal concentration>4000 ng/mL (FIG.4). Pharmacokinetic analysis of tumour tissue showed a maximal exposureof Compound 25 six hours after dosing, with a maximal concentration>3000ng per gram of tumour tissue (FIG. 5).

Western blot analysis (FIG. 6) shows a reduction in level ofphosphorylated STAT1 at t=1 h, returning to normal in comparison withvehicle treated controls between 6 and 24 h. An increase in cleavedParp, relative to vehicle treated controls, was observed between 1 and24 h in animals dosed with compound 25. Phosphorylated TYK2 levels wereincreased at 24 h following the initial dose. The data are consistentwith Compound 25 interacting at the ATP binding site of TYK2, leading toa reduction in phosphorylated STAT1 and increased apoptosis.

Example 7

Efficacy Study in Male SCID Mice Bearing MOLT-4 Tumours

MOLT-4 cells (1×10⁷ in matrigel) were implanted onto the rear dorsum ofmale SCID mice using a 25-gauge needle. When tumours reachedapproximately 100 mm³ the mice were randomly assigned to the followingtreatment groups.

Treatment Groups:

No of Dosing Group Drug Dose Schedule animals solution 1 Vehicle only —BID 10 — 2 Cyclo- 150 mg/kg  Q5D 10 15 mg/ml phosphamide 3 Compound 2525 mg/kg BID 10 2.5 mg/m l 4 Compound 25 50 mg/kg BID 10  5 mg/ml

Compound 25 was dosed twice daily per os for 21 days. Tumours invehicle-treated animals grew steadily during the study. Compound 25demonstrated good efficacy in controlling MOLT-4 tumour growth. A doseresponse was observed following treatment with Compound 25 with 50 mg/kgresulting in tumour regression and 25 mg/kg slowing growth but notresulting in tumour regression. At the end of the study period T/C (testversus control) values were 63.5% for Compound 25 at 25 mg/kg, and 27.0%at 50 mg/kg and 51.7% for cyclophosphamide. At day 21 tumour volume wassignificantly smaller in all treatment groups than those observed inanimals treated with vehicle only (p<0.0001 in all cases, ANOVA withTukey post-hoc test).

At the end of the study tumour tissue was resected and weighed. Tumourweights followed a similar pattern to tumour volume. T/C (test versuscontrol) values were 60.7% for Compound 25 at 25 mg/kg, 24.0% at 50mg/kg, and 49.0% for cyclophosphamide. At day 21 tumour weight wassignificantly smaller in all treatment groups than those observed inanimals treated with vehicle only (p<0.0001 in all cases, ANOVA withTukey post-hoc test).

Example 8

Tumour Growth Delay Study in Male SCID Mice Bearing CCRF-HSB-2 Tumours

A total of 40 male SCID mice aged 5-7 weeks were used for the study.These were purchased from Charles River and allowed to acclimatize for 7days prior to tumour implantation. Animals were housed in IVC cages (upto 5 per cage) with individual mice identified by tail mark. All animalswere allowed free access to a standard certified commercial diet andsanitised water during the study. The holding room was maintained understandard conditions: 20-24° C., 40-70% humidity and a 12 h light/darkcycle.

CCRF-HSB-2 cells (5×10⁶ in matrigel) were implanted onto the rear dorsumof male SCID mice using a 25-gauge needle. When tumours reached a sizeof approximately 100-150 mm³ the mice were randomly assigned to thefollowing treatment groups.

Route of No. of Dosing Group Drug Dose Schedule Administration Animalssolution 1 Vehicle only — BID PO 10 — 2 Cyclophosphamide 150 mg/kg  Q5DIP 10  15 mg/ml 3 Compound 29 25 mg/kg BID PO 10 2.5 mg/ml 4 Compound 2950 mg/kg BID PO 10   5 mg/ml

Dosing solutions were prepared on the day of study. Formulation was 0.5%methylcellulose/0.025% Tween-20 at dosing volume of 10 ml/kg based onanimal weight on day of dosing. Animals were dosed orally twice daily(12 hours apart) for 18 consecutive days.

Results

While animals treated with the positive control compound,cyclophosphamide, lost weight this was not significant. None of thecompounds tested at either dose had any effect on animal bodyweight.

Tumours in vehicle-treated animals grew steadily during the study (FIG.8). Example 29 demonstrated good efficacy in controlling CCRF-HSB-2tumour growth during the study, but both 25 and 50 mg/kg BID resulted insimilar levels of tumour growth inhibition. At Day 18 mean tumour sizesin both treatment groups were not statistically different (p=0.6397,2-way ANOVA with Tukey's post-hoc test).

At the end of the study period T/C (test versus control) values were18.1% for Compound 29 at 25 mg/kg, 10.8% for Compound 29 at 50 mg/kg and5.9% for cyclophosphamide.

At Day 18 tumour weight was significantly smaller in animals treatedwith Compound 29 at both 25 and 50 mg/kg BID than those observed inanimals treated with vehicle only (p<0.0001, ANOVA with Tukey post-hoctest) (see FIG. 9).

Example 9

Tumour Growth Delay STUDY in Male SCID Mice Bearing MOLT-4 Xenografts

A total of 50 male SCID mice aged 5-7 weeks were used for the study.These were bred in-house at Axis Bioservices. Animals were housed in IVCcages (up to 5 per cage) with individual mice identified by tail mark.All animals were allowed free access to a standard certified commercialdiet and sanitised water during the study. The holding room wasmaintained under standard conditions: 20-24° C., 40-70% humidity and a12 h light/dark cycle.

MOLT-4 cells (1×10⁷ in matrigel) were implanted onto the rear dorsum ofmale SCID mice using a 25-gauge needle. When tumours reachedapproximately 100-150 mm³ the mice were randomly assigned to thefollowing treatment groups.

Route of Admini- No. of Group Drug Dose Schedule stration Animals 1Vehicle only — BID PO 10 2 Cyclo- 150 mg/kg  Q5D IP 10 phosphamide 3Compound 29 25 mg/kg BID PO 10 4 Compound 29 50 mg/kg BID PO 10 5Compound 29 + 25 mg/kg + BID + PO 10 Cyclo- 150 mg/kg Q5D phosphamide

Dosing solutions were prepared on the day of study. The formulation forCompound 29 was 0.5% methylcellulose/0.025% Tween-20 at a dosing volumeof 10 ml/kg based on animal weight on day of dosing. The dosing matrixusing this formulation was a milky suspension.

The formulation for cyclophosphamide was PBS at a dosing volume of 10ml/kg based on animal weight on day of dosing. The dosing matrix usingthis formulation was a clear solution.

For combination dosing, both compounds were dosed at the same time.

Animals were dosed with Compound 29 orally twice daily (12 hours apart)for 21 consecutive days.

Results

Bodyweight in animals treated with Compound 29 at both 25 and 50 mg/kgwas maintained at pre-treatment levels during the study. In animalsreceiving combination of Compound 29 at 25 mg/kg and cyclophosphamide,mean bodyweight decreased to a nadir of 91% pre-treatment levels beforeincreasing slightly to 95% by the end of the study. One animal receiveda dosing holiday on Day 8. Although some bodyweight loss was observed,there were no adverse effects noted in terms of animal condition orbehaviour during the study.

Tumours in vehicle-treated animals grew steadily during the study (FIG.10). At the end of the study, tumours from all treatment groups weresignificantly smaller than the vehicle control groups. (p<0.0001 for allgroups; 2-way ANOVA with Tukey's post-hoc test). There was nosignificant difference between the monotherapy treatment groups at theend of study (2-way ANOVA with Tukey's post-hoc test). The tumours inthe study using Compound 29 at 25 mg/kg BID in combination withcyclophosphamide 150 mg/kg Q5D group were significantly slower than therespective monotherapy groups (p=0.0034 compared to cyclophosphamide and0.0043 compared to Compound 29 25 mg/kg QD by 2-way ANOVA with Tukey'spost-hoc test).

At the end of the study period T/C (test versus control) values were26.2% for cyclophosphamide, 16.6% for Compound 29 50 mg/kg BID, 26.8%for Compound 29 25 mg/kg BID and −2.1% for the combination group. Alltreatment groups show significant anti-cancer activity as defined by theNCI, which states that any compound which has a T/C value of less thanor equal to 42% has demonstrated significant anti-cancer activity.

Tumour tissue wet weight at the end of the study followed a similarpattern to measured tumour volume. Tumour weight in all treated groupswas significantly lower than in vehicle controls (p<0.0001 in all cases,ANOVA with Tukey post-hoc test) (see FIG. 11).

Example 10

Pharmaceutical Formulations

(i) Tablet Formulation

A tablet composition containing a compound of the formula (1) or formula(2) or a pharmaceutically acceptable salt thereof is prepared by mixing50 mg of the compound with 197 mg of lactose (BP) as diluent, and 3 mgmagnesium stearate as a lubricant and compressing to form a tablet in aknown manner.

(ii) Capsule Formulation

A capsule formulation is prepared by mixing 100 mg of a compound of theformula (1) or formula (2) or a pharmaceutically acceptable salt thereofwith 100 mg lactose and filling the resulting mixture into standardopaque hard gelatin capsules.

(iii) Injectable Formulation I

A parenteral composition for administration by injection can be preparedby dissolving a compound of the formula (1) or formula (2) (e.g. in asalt form) in water containing 10% propylene glycol to give aconcentration of active compound of 1.5% by weight. The solution is thensterilised by filtration, filled into an ampoule and sealed.

(iv) Injectable Formulation II

A parenteral composition for injection is prepared by dissolving inwater a compound of the formula (1) or formula (2) (e.g. in salt form)(2 mg/mL) and mannitol (50 mg/mL), sterile filtering the solution andfilling into sealable 1 mL vials or ampoules.

(iv) Sub-Cutaneous Injection Formulation

A composition for sub-cutaneous administration is prepared by mixing acompound of the formula (1) or formula (2) with pharmaceutical gradecorn oil to give a concentration of 5 mg/mL. The composition issterilised and filled into a suitable container.

EQUIVALENTS

The foregoing examples are presented for the purpose of illustrating theinvention and should not be construed as imposing any limitation on thescope of the invention. It will readily be apparent that numerousmodifications and alterations may be made to the specific embodiments ofthe invention described above and illustrated in the examples withoutdeparting from the principles underlying the invention. All suchmodifications and alterations are intended to be embraced by thisapplication.

1-14. (canceled)
 15. A method for the treatment or prophylaxis of acancer characterised by abnormally elevated levels of any one or more ofphosphorylated STAT1, phosphorylated STAT3 and phosphorylated STAT5,which method comprises administering to a patient, optionally incombination with radiotherapy or another chemotherapeutic agent, atherapeutically effective amount of a compound of formula:

or a pharmaceutically acceptable salt thereof
 16. A method according toclaim 15 wherein the method comprises inhibiting TYK2 kinase in thepatient.
 17. A method of alleviating or reducing the incidence of acancer characterised by abnormally elevated levels of any one or more ofphosphorylated STAT1, phosphorylated STAT3 and phosphorylated STAT5and/or BCL2 in a subject in need thereof, which method comprisesadministering to the subject a therapeutically effective amount ofcompound of the formula:

or a pharmaceutically acceptable salt thereof.
 18. A method according toclaim 17 wherein the method comprises inhibiting TYK2 kinase in thesubject.
 19. A method according to claim 17 wherein the subject is ahuman subject.
 20. A method according to claim 18 wherein the subject isa human subject.
 21. A method for the treatment or prophylaxis of acancer characterised by abnormally elevated levels of BCL2, which methodcomprises administering to a patient, optionally in combination withradiotherapy or another chemotherapeutic agent, a therapeuticallyeffective amount of a compound of the formula:

or a pharmaceutically acceptable salt thereof
 22. A method according toclaim 21 wherein the method comprises inhibiting TYK2 kinase in thepatient.
 23. A method according to claim 21 wherein the patient is ahuman patient.
 24. A method according to claim 22 wherein the patient isa human patient.
 25. A method for the treatment, or alleviating orreducing the incidence of, a cancer in a subject wherein the cancer ischaracterised by constitutive phosphorylation of STAT3, which methodcomprises administering to the subject an effective therapeutic amountof a compound of the formula:

or a pharmaceutically acceptable salt thereof.
 26. A method according toclaim 25 wherein the method comprises inhibiting TYK2 kinase in thesubject.
 27. A method according to claim 25 wherein the subject is ahuman subject.
 28. A method according to claim 26 wherein the subject isa human subject.